西双版纳片断热带雨林中鸟类物种多样性研究

1993年10-11月和1994年3-5月在西双版纳州曼俄龙山、城子龙山、曼养广龙山及保护区对照样地进行鸟类调查时, 观察到鸟类104种, 隶属27科, 另4亚科, 8目, 香农多样性指数以保护区对照样地为最高, 曼俄龙山和城子龙山为次, 曼养广龙山为最低. 均匀度也呈现相同的变化趋势. ｔ检验表明曼俄龙山和城子龙山的香农多样性指数无显著性差异. 3个龙山和保护区对照样地共有的种类11种, 3个龙山的共有鸟类为11种. 片断热带雨林中鸟类的多样性受多种因素共同影响, 片断热带雨林的面积、距较大原始雨林的距离、植物多样性和人为干扰程度以及周围的环境条件等因素均对鸟类多样性有影响。

Sensitivity of Total-Dose Radiation Hardness of SIMOX Buried Oxides to Doses of Nitrogen Implantation into Buried Oxides

In order to improve the total-dose radiation hardness of the buried oxides(BOX) in the structure of separa tion-by-implanted-oxygen(SIMOX) silicon-on-insulator(SOI), nitrogen ions are implanted into the buried oxides with two different doses,2 × 1015 and 3 × 1015 cm-2 , respectively. The experimental results show that the radiation hardness of the buried oxides is very sensitive to the doses of nitrogen implantation for a lower dose of irradiation with a Co-60 source. Despite the small difference between the doses of nitrogen implantation, the nitrogen-implanted 2 × 1015 cm-2 BOX has a much higher hardness than the control sample (i. e. the buried oxide without receiving nitrogen implantation) for a total-dose irradiation of 5 × 104rad(Si), whereas the nitrogen-implanted 3 × 1015 cm-2 BOX has a lower hardness than the control sample. However,this sensitivity of radiation hardness to the doses of nitrogen implantation reduces with the increasing total-dose of irradiation (from 5 × 104 to 5 × 105 rad (Si)). The radiation hardness of BOX is characterized by MOS high-frequency (HF) capacitance-voltage (C-V) technique after the top silicon layers are removed. In addition, the abnormal HF C-V curve of the metal-silicon-BOX-silicon(MSOS) structure is observed and explained.

溶胶-凝胶法制备LaAlO_3超微粉末

用溶胶-凝胶法低温合成多组分氧化物玻璃的详细工艺已有报导。我们亦成功地用该法制备出了钕玻璃薄膜和钕玻璃纤维。本文报道利用此法低温合成LaAlO_3超微粉末的研究结果。

Identification of a quasiparticle band in very neutron-rich Zr-104

The high spin levels of a very neutron-rich Zr-104 nucleus have been reinvestigated by measuring the prompt. rays in the spontaneous fission of Cf-252. The ground-state band has been confirmed. A new sideband has been identified with a band-head energy at 1928.7 keV. The projected shell model is employed to investigate the band structure of Zr-104. The results of calculated levels are in good agreement with the experimental data, and suggest that the new band in Zr-104 may be based on the neutron nu 5/2(-)[532] circle times nu 3/2(+)[411] configuration.