杜氏藻同步化生长及核型分析

经１２ｈ光照和１２ｈ黑暗的光周期诱导，杜氏藻（Ｄｕｎａｌｉｅｌａ）出现同步化生长．以０．０５％秋水仙素处理、低渗及高位（６０ｃｍ）滴片，获得４种杜氏藻的核型．它们都是单倍体．染色体大多呈圆点状，极小．最长的染色体约为１．６μｍ，最短的染色体仅约０．５μｍ．染色体数分别是：Ｄ．ｐａｒｖａ１６条，Ｄ．ｂｉｏｃｕｌａｔａ２２条，Ｄ．ｐｅｉｒｃｅｉ２６条和Ｄ．ｍｉｎｕｔａ２８条．只有Ｄ．ｐｅｉｒｃｅｉ的第１至第４号和第７号染色体可见较明显的中间缢痕     

量子点作为生物荧光探针的应用研究

量子点作为一种能发射荧光的半导体纳米微晶体,具有独特的光学性质。这决定了它在生物研究中有广阔的诱人的前景:如替代传统的生物荧光探针,具有荧光光谱较窄、量子产率高、不易漂白等优点;进一步讨论了量子点的电泳和微流控芯片的生物应用及其前景。     

基于RBF神经网络的结构可靠度分析方法

蒙特卡罗模拟是目前结构可靠度分析中最准确有效的方法,但因其计算量太大、效率低而受到很大的限制,特别是对于大型复杂结构的功能函数不能被明确表达的情况.鉴于此,在蒙特卡罗重要抽样方法的基础上,提出了利用RBF神经网络替代原结构功能函数的RBF-蒙特卡罗方法,以提高工作效率.RBF神经网络训练样本的选取则由均匀试验设计确定,以提高样本的代表性并大幅减少样本数量,从而加快网络的训练过程,加强网络的逼近能力.算例分析表明,该方法不但能最大限度地减少结构有限元分析次数,而且有满意的计算精度,具有实际应用价值.     

Nonnegative matrix factorization and its applications in pattern recognition

Matrix factorization has been widely used in many fields[1]. In numerical algebra, the large-scale and com- plex problems can be transformed into small-scale sim- ple subproblems by matrix factorization; in applied statistics, low rank approximation of or…     

硬脂酸/二氧化硅复合相变材料的制备

采用溶胶-凝胶法，制备了硬脂酸／SiO2复合相变材料．分别应用差示扫描量热仪（DSC）红外光谱仪（IR）和扫描电镜（sEM）测试了所制备复合材料的相变温度、相变焓、相变可逆性和微观结构．DSC测试结果表明该复合材料具有较好相变可逆性，相变焓和相变温度与纯硬脂酸相比均有降低．IR分析表明硬脂酸与二氧化硅之间是简单的嵌合关系．SEM表明复合材料表面具有多孔结构，改善了复合材料的相变可逆性。     

冬小麦田间小气候与大气候比较研究

通过对冬小麦拔节后期、孕穗期和成熟期田间活动面和1．5m高的气温和相对湿度与标准气象站对应要素作了同步观测和分析，找出各生育时段的差异，为将公共气象信息转换成作物环境信息提供了依据。     

Comparative physical mapping of rice BAC clones linked to resistance genes Glh,Bph-3 and xa-5 in Oryza sativa L. and O. granulata Nees et Arn. ex Watt.

Oryza granulata Nees et Arn. ex Watt. is one of the three wild relatives of rice,which are the most valuable for study and utilization in China.In this study,the homology and physical locations of three rice resistance genes,Glh,Bph-3 and xa-5 are comparatively analyzed between O.sativa and O. granulata by Southern blotting and fluorescence in situ hybridization (FISH).The results of Southern blotting indicate that there exist homologous sequences of the tested RFLP markers in O. granulata.By using three bacterial artificial chromosome (BAC) clones scanned by the tested RFLP as probes, FISH signals are detected on both mitotic and pachytene chromosomes in O.sativa and O.granulata.Dual-color FISH demonstrates that two of the three BAC clones (14E16 and 38J9) are located on the short arm of the same chromosome pair in O. granulata. Additionally, colinearity is shown for the two clones between O.sativa and O.granulata. Another BAC clone 44B4 is located on the end of the short arm of other chromosome pair in these two species.Although the phylogenetic relationship between O.sativa and O.granulata is the most distinct in Oryza and these two species have evidently different biological features and ecological habits, the relative lengths and arm ratios of the detected chromosomes and the relative positions of the tested clone signals on chromosomes in O. granulata are quite similar to those in O. sativa.     

高斯背景下距离扩展目标的恒虚警率检测

对宽带高分辨率雷达(HRR)中的距离扩展目标进行检测,若还采用分辨雷达的检测方案,目标回波的全部能量得不到充分利用,会影响雷达的检测性能。提出了一类基于二进制积累的距离扩展目标检测算法,推导出了它们的平均虚警概率和平均检测概率的数学解析式,并进行了性能分析和比较。这些方法较常规低分辨雷达方法可获得目标信噪比8个多分贝的性能改善,且这些次优积累的高分辨雷达距离扩展目标检测方法具有易于工程实现的优点。     

几种简化联合概率数据互联算法性能分析

针对最优联合概率数据互联算法复杂、运算量大的问题,目前提出了许多简化的联合概率数据互联算法。为了清楚地了解这些算法在不同环境下在跟踪精度、实时性等跟踪性能上的差异,对几种典型的简化算法进行了详细的性能分析。给出了简化算法的数学模型,然后从理论上对这些算法进行了优缺点比较,最后选取了多种典型的与实际工程背景相近的多目标运动环境,对几种比较有代表性的简化算法在这些环境下进行仿真实验,并根据仿真结果对它们各方面的性能进行综合分析。     

New structure of Kalman filter for radar networking

1.INTRODUCTION Inpractice,radarsoftenoperateasynchronouslyandpro videdataatdifferentrateswithdifferentcommunication timedelays,thustheproblemofdatafusioninradarnet workingsystemisasynchronousinsteadofsynchronous. However,theresearchinthefieldofdatafusionfocuses onthesynchronousproblems,andthemeasurementsof differentsensorsarealwayspredictedatthesametimefor updatingKalmanfiltersynchronously.Thisapproachis complicatedforengineering,anditwillreducethedata ratesofthesystem,atthesametimethee…