蓝裸甲藻有性生殖的初步观察

<正> 早在1879年,Joseph就描述了Peridinium stygium的配子融合现象。之后的近八十年中,对甲藻生活史中是否存在有性生殖一直存在着争论。直至Von Stosch(1964)报道了Ceratium horridium和C.cornutum有性生殖核配的详细过程后,甲藻的有性生殖才得到公认。迄今,至少已在15属30种甲藻的生活史中观察到有性阶段。 Andersoa等人经大量的研究,证明:Gonyaulax tamarensis的周期性赤潮起源于海底沉积物中的休眠合子。在Gonyaula

引起橡胶和马尾松木材蓝变的真菌—可可球二孢

<正> 可可球二泡(Botryodiplodia theobromae Pat.)早在1879年就被Cooke发现,目前,至少拥有48个异名,常见的异名是Diplodia theobromae(Pat.)Nowell,Diplodia natalensis PoleEvans,Lasiodiplodia theobromae(Pat.)Griff.＆ Maubl。Punithalingam和Sutton分别对该菌作过详细的评述。它广泛分布于热带、亚热带和温带。其寄主植物已知约500种,它不但引起植物病害,

A study on the economic efficiency of hydrogen production from biomass residues in China

As part of Pilot Project of KIP of CAS, a feasibility study of hydrogen production system using biomass residues is conducted. This study is based on a process of oxygen-rich air gasification of biomass in a downdraft gasifier plus CO-shift. The capacity of this system is 6.4 t biomass/d. Applying this system, it is expected that an annual production of 480 billion N m(3) H-2 will be generated for domestic supply in China. The capital cost of the plant used in this study is 1328$/(N m(3)/h) H-2 out, and product supply cost is 0.15$/N m(3) H-2. The cost sensitivity analysis on this system tells that electricity and catalyst cost are the two most important factors to influence hydrogen production cost.

一种基于高维空间覆盖动态搜索方法的非特定人连续数字语音识别的研究

本文使用高维空间点分布分析原理，在仿生模式识别高维空间点覆盖原理的基础上，提出了一种基于高维空间点覆盖动态搜索理论的非特定人连续数字语音识别的新算法，这种算法可以不经过端点检测和分割，通过对被识别连续数字语音直接进行动态搜索，得到被识别语音到各类高维空间覆盖范围的距离随时间变化曲线，通过距离曲线上的极小值点进行识别．

掺杂分子束外延GaAs薄膜表面和GaAs-GaAs界面的光反射调制谱

国家自然科学基金

细铂丝表面池沸腾临界热流尺度效应研究

本文实验研究了地面重力环境中过冷度和加热铂丝直径对FC-72和丙酮池沸腾传热临界热流现象的影响. 实验结果表明,临界热流具有明显的尺度效应,其特征随Bond数范围的不同而不同,但具体的分区准则依赖于工质的物性. 在中等和大的Bond数区域,过冷度对临界热流的影响与铂丝直径无关;而在小Bond数区域,过冷度效应与尺度明显相关

Modal correction for fiber-coupling efficiency in free-space optical communication systems through atmospheric turbulence

High-speed free-space optical communication systems have recently used fiber-optical components. The coupling efficiency with which the received laser beam can be coupled into a single-mode fiber is noticeably limited by atmospheric turbulence due to the degradation of its spatial coherence. Fortunately, adaptive optics (AO) can alleviate this limitation by partially correcting the turbulence-distorted wavefront. The coupling efficiency improvement provided by Zernike modal AO correction is numerically evaluated. It is found that the first 3-20 corrected polynomials can considerably improve the fiber-coupling efficiency. The improvement brought by AO is compared with that brought by a coherent fiber array. Finally, a hybrid technique that integrates AO and a coherent fiber array is proposed. Results show that the hybrid technique outperforms each of the two above-mentioned techniques. (C) 2009 Elsevier GmbH. All rights reserved.