IDX法测定湿地松种子生活力的研究

以水作衬比剂，对湿地松（Ｐｉｎｕｓ ｅｌｌｉｏｔｔｉ Ｅｎｇｅｌｍ）种子进行ＩＤＸ法检验其生活力的研究，结果表明：湿地松种子在２５℃水中浸２ｈ后，置床培养４８ｈ，用吸水纸吸去表面水份，用硅胶干燥９ｈ（３０℃），其Ｘ射线片上死活种子图像差异显著，其判读结果与发芽率基本一致。     

谈排球规则的修改对技战术的影响

根据排球规则修改的内容，提出了将会出现的队员发球位置改变，脚踢球的现象，软式传球的合法化，以及新的战术配合等技术和战术。新规则使排球运动攻守更趋于平衡。     

Structure characterization of melt drawn polyethylene ultrathin films

Highly oriented ultrathin polyethylene (PE) films were prepared by a melt-draw technique. Transmission electron microscopy study on the obtained ultrathin films indicates that the melt drawn PE thin films consist of highly oriented edge-on lamellae aligned perpendicular to the drawing direction. Electron diffraction confirms that the PE chains in crystal-line phase are highly oriented in film plane along the drawing direction, while only a random orientation of the crystallographic a-and b-axes can be described through electron diffraction. The IR results on the melt-drawn ultrathin PE films demonstrate that the PE molecular chains in both crystalline and amorphous phases of the melt drawn thin films are well oriented along the drawing direction. Moreover, the IR results indicate that in the crystalline phase, the crystallographic b-axis tend to lie in the thin film plane, while in the amorphous phase, the skeleton plane of some local chains prefers to parallel the film plane. The alignment of b-axis of PE crystals in ultrathin films originates from the fact that the b-axis is the fastest growth direction of the PE crystals.     

A new improved structure of dye-sensitized solar cells with reflection film

DYE-SENSITIZED NANOCRYSTALLINE SOLAR CELLS (DSSC), RECENTLY DEVELOPED BY MICHAEL GR?TZEL[1], HAVE BEEN ATTRACTING CONSIDERABLE ATTENTIONS BECAUSE OF ITS HIGH EFFICIENCY, SIMPLE FABRICATION PROCESS AND LOW FABRICA- TION COST[2]. TYPICAL DSSC[3] IS BASED ON A SANDWICH STRUCTURE, WHICH CONSISTS OF TWO GLASS PLATES WITH A TRANSPARENT CONDUCTING OXIDE (TCO) COATING AS SUBSTRATE. O…     

低信噪比图像中运动点目标的检测方法

图像中点目标的检测是目前比较活跃的研究领域,它在制导、天文观测、遥感等学科中有着重要的应用价值。在低信噪比条件下,要从图像中检测出运动的点目标存在着不少困难。本文首先分析了低信噪比情况下检测的难点,然后对目前七种有代表性的方法加以评介。     

箔条云极化识别方案性能分析

反航导弹雷达导引头识别箔条云新方案──极化识别方案是建立在箔条云和舰艇去极化特性具有显著差异基础上的。为了分析该方案所能达到的性能，本文首先采用严格的理论方法分析箔条云的去极化特性，并定义去极化系数和推导去极化系数的概率密度函数。在此基础上，构造了一个用于识别箔条云与舰艇的最大似然检测系统，并对该系统的错误概率进行了计算。最后讨论降低错误概率的几种途径，重点讨论了序列检测方法。研究结果表明，该方法较好地解决了提高识别性能与缩短观测时间的矛盾。     

自然科学领域著名期刊简介--Science周刊

Science杂志于 1880年创刊 ,现由美国科学促进会 (TheAmericanAssociationfortheAdvancementofScience,AAAS)主办 ,是具有科学新闻和学术期刊双重特点的国际性周刊 ,也是世界上传播范围最广的科学刊物之一 ,以发表具有重要意义的原创性科研报告为主。本文旨在介绍该刊的办刊宗旨、征稿要求及评审程序 ,以期能够更好地了解Sci ence,提高投稿率和录用率 ,把我们出色的科研成果展示给世界 ;同时也能够通过阅读Science,把握最前沿的科学研究动态 ,加强我国与世界科学界的联系。     

举龙头建基地推进小麦优质化和产业化进程

实现小麦优质化和产业化开发是一个系统工程，有关部门应从企业增效、农民增收的角度出发，为优质专用小麦的开发创造良好环境。     

通过工程实践,提高学生综合素质

突破传统的实验课教学模式,以科研项目为基础,结合重点实验室及学科建设,进行以综合性实验为特色的工程实践活动,达到拓展知识面,培养创新意识,提高分析、处理问题的能力,使学生形成科学的思维方式、严谨踏实的科学作风,提高其综合素质.