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111.
A two-dimensional direction-of-arrival (DOA) and polarization estimation algorithm for coherent sources using a linear vector-sensor array is presented. Two matrices are first constructed by the receiving data. The ranks of the two matrices are only related to the DOAs of the sources and independent of their coherency. Then the source’s elevation is resolved via the matrix pencil (MP) method, and the singular value decomposition (SVD) is used to reduce the noise effect. Finally, the source’s steering vector is estimated, and the analytics solutions of the source’s azimuth and polarization parameter can be directly computed by using a vector cross-product estimator. Moreover, the proposed algorithm can achieve the unambiguous direction estimates, even if the space between adjacent sensors is larger than a half-wavelength. Theoretical and numerical simulations show the effectiveness of the proposed algorithm. 相似文献
112.
多管火箭发射动力学普遍方程的研究 总被引:2,自引:0,他引:2
多管火箭武器系统的总体论证,总体设计,需要对系统进行发射动力学分析。该文用图论的观点分析多管火箭发射系统的结构,用多刚体动力学的分析方法,把多管火箭系统风化为火箭弹,俯仰部分,回转部分和载体部分4部分刚体,适当改进了多刚体动力学中动力学增广体的概念,使之更适合于多管火箭武器这一特殊系统的发射动力学分析。 相似文献
113.
马宝成分与结构的分析研究 总被引:1,自引:0,他引:1
本文用等离子发射光谱法同时分析了马宝中二十一种无机微量元素,并用X衍射仪进行了结构分析,结果表明,真,伪马宝中无机成分差异较大,结构也有明显区别. 相似文献
114.
TAO Jun WANG Zhan-lin 《武汉大学学报:自然科学英文版》2005,10(5):877-882
This paper analyzes PROFIBUS-DP network delay in detail and presents the calculational formula of its maximum time-delay, which is significant to the research of PROFIBUS-DP. At the same time, the paper puts forward a method of simplifying the network induced time-varying indeterminate system according to the features of the network. Through the analysis of a pump-control-motor system which is composed of PROFIBUS-DP network, it illustrates the network's influence on the performance of control systems. This method helps to design and analyze the network's influence on the performance of control systems, which is of considerable practical value in a time when network control systern is widely used. 相似文献
115.
QTL mapping of resistance to sheath blight in maize(Zea mays L.) 总被引:2,自引:0,他引:2
YANG Hua YANG Junpin RONG Tingzhao TAN Jun & QIU Zhenggao . Corn Institute of Sichuan Agricultural University Ya’an China . Crops Institute of Sichuan Academy of Agricultural Science Chengdu China . Chongqing Academy of Agricultural Science Chongqing China 《科学通报(英文版)》2005,50(8):782-787
Maize sheath blight (Rhizoctonia Solani) is a widely occurring fungus disease with great harm to corn-pro- ducing regions in the world. The first happening of sheath blight in China was reported in Jilin Province as early as in 1966[1]. Since the 1970s, the enlargement of corn- growing regions, the application of maize hybrids, the increasing use of fertilizers, especially the nitrogenous fertilizer, and a higher growth-density, all have caused a quick spread of sheath blight, the occurring … 相似文献
116.
Li Jun |e Zhou Dong |ru . Computer Center Wuhan University Wuhan Hubei China . School of Computer Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2003,8(3):791-796
0 IntroductionSincethemostservicesinInternetareofferedviaWeb ,WorldWideWebbecomesmoreimportantthanbefore.TheWebsitestructureisbecomingmorecomplex .InWebsite’splanninganddesigning ,theWebsitestructureisdependantonthedesigner’sexperienceforlackingofmodelandmethod,whichleadstounreasonableWebstructureforusersaccessingandlossesmanyvisitors.Itisagreatpityforcommercesiteorenterprisebusinesssite.Fromtheviewofthepointofsoftwareengineering ,theperformanceofWebsiteshouldbeevaluatedineveryperiodof… 相似文献
117.
为研究红莲型水稻细胞质雄性不育的分子基础,我们提取纯化了红莲型水稻丛广41A和丛广41B的线粒体DNA,采用限制性内切酶酶切片段长度多态性(RFLP)方法比较了红莲型不育系和保持系线粒体DNA酶切图谱,发现两者之间存在一定的差异,部分支持了细胞质雄性不育与线粒体DNA有关的结论。 相似文献
118.
Complex Nuclear Fuel Cycle (NFC) system faces many socio-technical issues that need to obtain the consensus between stakeholders of different knowledge background. In this paper, a visualized analysis platform based on graphical functional modeling method, Multilevel Flow Model (MFM), is proposed to help those stakeholders to recognize and analyze various socio-technical issues in NFC system. Some new functions, such as “Reaction Function”, “Switch Function” and “Conversion Function”, are introduced to fulfill new simulation tasks for NFC system. Based upon this methodology, a micro-process and a macro-process of NFC system are simulated and meanwhile some key analysis variables, such as CO2 emission and cost flow, required by some analysis methods are deducted and displayed in the platform. And finally a sample simulation analysis is conducted based on MFM. 相似文献
119.
Excitatory effect of histamine on neuronal activity of rat cerebellar fastigial nucleus in vitro 总被引:1,自引:0,他引:1
TANG Biao ZHANG Jun LI HongZhao ZHU JingNing & WANG JianJun Department of Biological Science Technology/State Key Laboratory of Pharmaceutical Biotechnology School of Life Sciences Nanjing University Nanjing China Jiangsu Key Laboratory for Bioresource Technology School of Life Sciences Nanjing Normal University Nanjing China 《科学通报(英文版)》2007,52(4):497-503
The cerebellar fastigial nucleus (FN) holds an important role in motor control and body balance. Previous studies have revealed that the nucleus is innervated by direct hypothalamocerebellar histaminergic fibers. However, the functional role of histaminergic projection in cerebellar FN has never been established. In this study, we investigated the effect of histamine on neuronal firing of cerebellar FN by using slice preparations. Sixty-five FN cells were recorded from 47 cerebellar slices, and a vast majority of the cells responded to histamine stimulation with an excitatory response (58/65, 89.2%). Perfusing slices with low-Ca2 /high-Mg2 medium did not block the histamine-induced excitation (n=10), supporting a direct postsynaptic action of histamine on the cells. Furthermore, the excitatory effect of histamine on FN neurons was not blocked by selective histamine H1 receptor antagonist triprolidine (n=15) or chlorpheniramine (n=10), but was effectively suppressed by ranitidine (n=15), a highly selective histamine H2 receptor antagonist. On the other hand, highly selective histamine H2 receptor agonist dimaprit (n=20) instead of histamine H1 receptor agonist 2-pyridylethylamine (n=16) mimicked the ex- citatory effect of histamine on FN neurons. The dimaprit-induced FN neuronal excitation was effectively antagonized by selective histamine H2 receptor antagonist ranitidine (n=13) but not influenced by se- lective histamine H1 receptor antagonist triprolidine (n=15). These results demonstrate that histamine excites cerebellar FN cells via the histamine H2 receptor mechanism and suggest that the hypotha- lamocerebellar histaminergic fibers may modulate cerebellar FN-mediated sensorimotor integration through their excitatory innervations on FN neurons. 相似文献
120.
Ultrasensitive monitoring of ribozyme cleavage product using molecular-beacon-ligation system 总被引:1,自引:0,他引:1
MENG XiangXian TANG ZhiWen WANG KeMin TAN WeiHong YANG XiaoHai LI Jun GUO QiuPing 《科学通报(英文版)》2007,52(5):603-607
This paper reports a new approach to detect ribozyme cleavage product based on the molecular-beacon-ligation system. The molecular beacon, designed in such a way that one-half of its loop is complementary to ribozyme cleavage product, is used to monitor ligation process of RNA/DNA com-plex in a homogeneous solution and to convert directly cleavage product information into fluorescence signal. The method need not label ribozyme and ribozyme substrate, which is fast, simple and ultra-sensitive for detection of cleavage product. Detection limit of the assay is 0.05 nmol/L. The cleavage product of hammerhead ribozyme against hepatitis C virus RNA (HCV-RNA) was detected perfectly based on this assay. Owing to its ultrasensitivity, excellent specificity, convenience and fidelity, this method might hold out great promise in ribozyme reaction and ribozyme gene therapy. 相似文献