采用多树结构的快速多假设跟踪算法

多假设跟踪算法是解决多目标跟踪问题的常用方法。算法在没有任何先验知识情况下,组合不同时刻量测形成假设航迹,依据关联规则判断所有假设航迹是否成立,从而跟踪目标。在实际关联过程中,量测数量增加会导致假设航迹数量出现组合爆炸现象,从而产生大量冗余计算。文章用多树结构实现多假设算法,利用树形结构特征快速剪枝,极大减少了错误假设的冗余计算量。     

Nonvolatile resistive switching memories-characteristics,mechanisms and challenges

<正>This review presents a summary of current understanding of the resistive switching materials and devices which have inspired extraordinary interest all over the world.Although various switching behaviors and different conductive mechanisms are involved in the field,the resistive switching effects can be roughly classified into filament type and interface type according to their conducting behavior in low resistance state.For those filament based systems,the migration of metallic cations and oxygen vacancies, characterization of the filament as well as the role of Joule heating effects are discussed in detail.As to the interface based system, we describe the methods of modulating interface barrier height such as using different electrodes,inserting a tunnel layer.It is demonstrated that the switching mechanism can transform from one to another along the change of some specific conditions.We also give an overview on the latest developments in multilevel storage and the resistive switching in organic materials.In this paper,the solutions to address the sneak current problems in crossbar structure are discussed.     

用林帮的副反应思想处理氧化还原滴定分析

用林帮的副反应思想处理氧化还原滴定分析,得到了和络合滴定相似的滴定曲线方程和终点误差公式,在理论上和络合滴定达到了统一,使氧化还原滴定理论完善,内容精练,体系科学.     

Oxidation and tyrosine phosphorylation: synergistic or antagonistic cues in protein tyrosine phosphatases

Protein tyrosine phosphatases (PTPs) have been generally recognised as key modulators of cell proliferation, differentiation, adhesion and motility. During signalling, several PTPs undergo two posttranslational modifications that greatly affect their enzymatic activity: tyrosine phosphorylation and cysteine oxidation. Although these modifications share their reversibility depending on the intracellular environment, their effects on enzymatic activity are opposite, tyrosine phosphorylation being correlated to enzyme activation and thiol oxidation to complete inactivation. Several papers have suggested that both these modifications occur in response to the same stimuli i.e. cell proliferation induced by numerous growth factors and cytokines. Conversely, the possibility that these two regulation mechanisms act simultaneously on PTPs has not been established and very few reports investigated this dual regulation of PTPs. To underline the relevance of the question, we discuss several possibilities: (i) that tyrosine phosphorylation and cysteine oxidation of PTPs may share the same target molecules but with different kinetics; (ii) that PTP phosphorylation and oxidation may take place on different subcellular pools of the same protein and (iii) that these two modifications, although having divergent effects on enzyme activity, cooperate in the integrated and coordinated function of PTPs during receptor tyrosine kinase signalling. We believe that our perspective will open new perspectives on an ancient problem – the apparent contradiction of opposing enzymatic regulation of many PTPs – thus clarifying their role as positive or negative transducers (or both) of many extracellular stimuli.Received 11 October 2004; received after revision 26 January 2005; accepted 10 February 2005 Available online 29 March 2005     

心肌缺血性损伤与硫氧还蛋白系统

心肌缺血时氧化应激对心肌细胞的影响包括对心肌细胞的损伤和对心肌细胞的保护.心肌细胞存活与死亡有赖于细胞的氧化还原状态,通过改变细胞内的氧化还原状态可干预氧化应激.Trx系统对机体内氧化还原调节及其重要,通过抗氧化和氧化还原调节作用,在基因表达、信号转导、细胞生长、细胞凋亡等方面起着重要作用.Trx系统自身也受到氧化还原调节.     

The initiation and connection of vessel elements in Arabidopsis thaliana （Brassicaceae） seedlings

This research used confocal laser scanning microscopy to examine the initiation and connection of vessel elements in Arabidopsis thaliana （L.） Heynh seedlings. The results indicated that vessel elements differentiated first in the lower portion of cotyledon-node zone （CNZ） 2 h after germination, and then extended downwards to the hypoeotyl and root and upwardly to the middle portion of CNZ. 10 h after germination, vessel elements developed in the lower portion of cotyledon blade, the second initiating site, connecting gradually with that initiated in cotyledon node and forming pinnate-marginal venation. The connection of vessel elements occurred between the upper portions of CNZ and epieotyl-shoot zone 7 d after germination. By then, the complete connection of vessel elements in the axial and lateral organs had formed.     

The discharge and charge behavior of the Pb-Birnessite in LiOH aqueous solution

0　IntroductionManganeseoxideshavebeenwidelystudiedasbatterycathodesbecauseofitslowcostandlowtoxicity .Muchefforthasbeenfocusedonthespinelphase ,γ MnO2 andse verallayeredmanganeseoxidesinaqueousandnon aqueous .Sothereismuchinterestinmanganeseoxidesforuseascathodematerialsforadvancedlithiumbatteriestoreplacetheexpensivelithiumcobaltornickelsystem .ButthespinelLixMn2 O4hasthelowerratecapabilityandlowertheoreti calcapacityandγ MnO2 hasunsatisfactoryreversibilityinaqueous,thereby ,theiradvant…     

几种聚合物光稳定剂的合成

依据光引发高分子聚合物老化机理，提出了合成在光照、有氧条件下适宜的抗老剂应具有的结构特征，探讨了合成条件，合成了三种哌啶酯类抗光老化助剂     

芳叔胺体系引发乙烯类单体聚合的机理——自旋捕集ESR法

采用自旋捕集ESR技术和紫外光谱法,研究了N,N-二甲基苯胺(DMA)-苄基氯(BC)引发甲基丙烯酸甲酯(MMA)自由基聚合的机理;DMA对MMA、丙烯酸甲酯(MA)、苯乙烯(St)及α-甲基苯乙烯(α-MeSt)烯类单体的引发作用。在60℃、无氧条件下、DMA-BC-MMA体系中可产生自由基其中仅有R3参与引发反应,由此证实了以前所提出的引发机理。DMA单独存在下与MMA、α-MeSt这些带有α-甲基的乙烯类单体也可形成活泼的自由基R3,并引发聚合;若与不带有α-甲基的乙烯类单体,如MA、St,则不能形成自由基R3,因此它们不能被引发聚合。     

氧化还原功能纤维的研究(IV)——含醇胺基功能纤维对Au~(3 )的氧化还原反应机理

通过元素分析、红外光谱、广角Ｘ－射线衍射、核磁共振波谱及光电子能谱等分析手段证实含醇胺基功纤维与Ａｕ３＋的氧化还原反应过程中，约有３３％的吸附态金被还原成单质，纤维上约有５．７％Ｃ＝Ｏ键形成，而氮原子未被氧化．即纤维上氮原子附近的羟基碳原子先被氧化生成了羰基．同时以氯甲基化纤维为基体的三甲胺基纤维对Ａｕ３＋无还原作用，再次证实羟基碳在氧化还原反应过程中起决定作用