稻田鱼腥藻返地克隆株的卫星再搭载研究

<正>稻田鱼腥藻(Anabaena oryza HB32)通过90105返回卫星搭载后出现性状分离,其中分离到AoSR16藻株,其固氮酶活力较对照(出发株)成倍提高,其光合和呼吸活性尚未发现明显差异.经2年的地面保持培养后,该藻株的固氮酶活性仍高于对照.1992年10月我们对AoSR16进行了卫星再搭载空间飞行.本文主要报道再搭载后,该藻株的性状分离情况及其再分离单克隆藻株固氮酶活性、生长速率、藻胆蛋白累积和氨排出的变化以及它们间的相互关系,并对固氮酶活性变化的原因及其生理生化效应进行了初步探讨.

Floral surveys on Gomphonemaceae and Cymbellaceae (Bacillariophyta) from the headwaters of the Yangtze River, Qinghai, China

Gomphonemaceae and Cymbellaceae from the headwaters of the Yangtze River, Qinghai Province, China, comprised 84 taxa belonging to four genera. The dominant species were Gomphonema kaznakowi Mer., G. hedini Hust., G. olivaceum (Lyngbye) Kutz., Cymbella cistula (Ehr.) Kirchn. var. cistula and C. minuta Hilse ex Rabh. var. minuta. Some arctic and alpine forms also occurred, and the following taxa were unique to this region: C. cistula var. asiatica Mer., C. cistula var. capitata Grun., C. yabe Skvortzow var. punctata Li and Shi, G. olivaceum (Lyngbye) Kutzing var. brevistriatum Li and Shi and G. staurophorum (Pant.) Cleve-Euler var. oblongum Li and Shi. Different morphological forms of G. kaznakowi Mer. may be related to the upheaval of the plateau. Species diversity of the diatoms appears to be related not only to macro-environment (e.g., geographic zonation) but also to microhabitat and microclimate.

Coulomb blockade double-dot Aharonov-Bohm interferometer: Giant fluctuations

Electron transport through two parallel quantum dots is a kind of solid-state realization of double path interference We demonstrate that the inter-clot Coulomb correlation and quantum coherence would result in strong current fluctuations with a divergent Fano factor at zero frequency. We also provide physical interpretation for this surprising result, which displays its generic feature and allows us to recover this phenomenon in more complicated systems. (C) 2009 Elsevier B.V. All rights reserved.

Controlled growth of III-V compound semiconductor nano-structures and their application in quantum-devices

This paper reviews our work on controlled growth of self-assembled semiconductor nanostructures, and their application in light-emission devices. High-power, long-life quantum dots (QD) lasers emitting at similar to 1 mu m, red-emitting QD lasers, and long-wavelength QD lasers on GaAs substrates have successfully been achieved by optimizing the growth conditions of QDs.

Dielectric properties of Bi2Ti2O7 films grown on Si(100) substrate by APMOCVD

The growth of Bi2Ti2O7 films with (111) orientation on Si(100) substrate by atmospheric pressure metal-organic chemical vapor deposition(APMOCVD) technique at 480similar to550 degreesC is presented. The films were characterized by X-ray diffraction analysis, atomic force microscopy and electron diffraction. The results show high quality Bi2Ti2O7 films with smooth shinning surface. The dielectric properties and C-V characterization of the films were studied. The dielectric constant (epsilon) and loss tangent (tgdelta) were found to be 180 and 0.01 respectively. The charge storage density was 31.9fC/mum(2). The resistivity is higher than 1x10(12) Omega. .cm under the applied voltage of 5V. The Bi2Ti2O7 films are suitable to be used as a new insulating gate material in dynamic random access memory (DRAM).

Quantum-well anisotropic forbidden transitions induced by a common-atom interface potential

A prominent effect of the interface potential (IP) [E. L. Ivchenko and A. Yu. Kaminski, Phys. Rev. B 54, 5852 (1996); O. Krebs and P. Voisin, Phys. Rev. Lett. 77, 1829 (1996)], the optical anisotropy of the forbidden transitions in quantum wells has been observed by reflectance-difference spectroscopy. Predictions by the heavy-light-hole coupling IP models are qualitatively consistent with all the observed features of the forbidden and the allowed transitions. The fact that the predicted value of the relative, transition strength, which depends on neither the IP strength nor the electric field, disagrees with the observed one indicates that coupling involving X and/or L bands may also be important. [S0163-1829(99)04227-7].

一种入侵容忍的CA方案

CA(certificate authority)是PKI中的关键设施.CA的私有密钥一旦泄露,该CA签发的所有证书就只能全部作废.保护在线服务CA的私钥也就成为一个非常重要的课题.不是从保护系统或检测入侵出发来保证CA的安全,而是确保当少数部件被攻击或占领后,CA系统的机密信息并没有暴露.通过将私钥分发给不同的部件,并保证任何一个在线的部件无法恢复CA的私钥,从而保护了CA私钥的保密性.

多级安全DBMS的通用审计策略模型

提出了一种基于多级安全数据库管理系统的通用审计策略模型．该模型具有丰富的表达能力，既可以表达基于时间的审计策略，也可以实现基于规则的审计策略推衍．通过引入对象的属性谓词，还可以表达细粒度的审计策略．证明了该模型的可判定性，并给出了判定任意一个事件是否需要审计的算法．

在Qt上实现蒙文显示的设计与实现

随着软件产业国际化进程的发展,在操作系统中实现对我国少数民族文字的显示是一项具有挑战性和刻不容缓的任务,针对这项任务先分析了少数民族文字中蒙古文的语法特点和书写特点、桌面系统平台库QT的体系结构特点以及OpenType字体文件的特点,在此基础之上提出在QT中使用OpenType字体文件来实现蒙古文显示的详细实现方案,最后给出了目前该方案在项目中的实现情况和效果,并阐述了还有哪些地方需要进一步研究和改进。

Hybrid numerical methods for exponential models of growth

A series of novel numerical methods for the exponential models of growth are proposed. Based on these methods, hybrid predictor-corrector methods are constructed. The hybrid numerical methods can increase the accuracy and the computing speed obviously, as well as enlarge the stability domain greatly. (c) 2005 Published by Elsevier Inc.

硅基1．55μm可调谐共振腔窄带光电探测器的研究

制作了一种低成本硅基1．55μm可调谐共振腔增强型探测器．首次获得硅基长波长可调谐共振腔探测器的窄带响应，共振峰量子效率达44%，峰值半高宽为12．5nm，调谐范围14．5nm，并且获得1．8GHz的高频响应．本制作工艺不复杂，成本低，有望用于工业生产．

Dielectric properties of Bi2Ti2O7 films grown on Si(100) substrate by APMOCVD

The growth of Bi2Ti2O7 films with (111) orientation on Si(100) substrate by atmospheric pressure metal-organic chemical vapor deposition(APMOCVD) technique at 480similar to550 degreesC is presented. The films were characterized by X-ray diffraction analysis, atomic force microscopy and electron diffraction. The results show high quality Bi2Ti2O7 films with smooth shinning surface. The dielectric properties and C-V characterization of the films were studied. The dielectric constant (epsilon) and loss tangent (tgdelta) were found to be 180 and 0.01 respectively. The charge storage density was 31.9fC/mum(2). The resistivity is higher than 1x10(12) Omega. .cm under the applied voltage of 5V. The Bi2Ti2O7 films are suitable to be used as a new insulating gate material in dynamic random access memory (DRAM).