巨轮型纳米多孔钼氧基多金属氧酸盐化合物表面活性部位的检测

利用谷氨酸盐为探针分子, 通过单晶X 射线结构解析、IR、元素分析、¹H NMR 和TG 等综合分析手段, 成功检测到可以看做MoO₃ 类似物的巨轮型纳米多孔钼氧基 多金属氧酸盐表面在特定条件下的反应活性点, 与此同时实现了用多官能团有机分子 对巨轮型金属氧簇内表面的功能型修饰. Z-扫描实验表明, 所得到的这种有机-无机杂 化化合物在能量为15 μJ 的532 nm 波长、18 ps 激光脉冲作用下, 具有显著的非线性光 学反饱和吸收和自聚焦响应.     

多机器人编队的人工势场法控制

针对多机器人编队控稍中的队形形成问题进行研究.利用控制算法中的人工势场法解决多机器人队形形成问题,结构简单、易于计算,方便对多机器人实时控制.首先,针对多机器人的队形位置用目标点搜索算法,寻找到正确的队形位置点,防止多机器人在空间内绕路,减少编队时间;然后,通过人工势场算法规划各机器人的路径,在机器人行进过程中,利用优先级蔽障方法避免与其他机器人碰撞;最后,对多机器人的队形形成进行仿真,实验证明队形形成的有效性,算法简单易于实现.     

基于点的方向图算法

提出了一种基于曲率的点方向初始值算法．该算法根据像素点在不同方向上的曲率变化确定该点的初始方向值,并明确提出了点方向的概念．提出了一种点方向图的新算法并研究了相应的快速算法．基于块划分的传统块方向图有时是不连续的．与块方向图相比,点方向图保留了块方向图的统计特性,又克服了块方向图的缺陷,不需要先进行背景分离,点方向计算与背景分离同步进行．     

DEX1, a plasma membrane-localized protein, functions in microspore development by affecting CalS5 expression in Arabidopsis thaliana

Microsporogenesis in flowering plants plays important roles in sexual reproduction. It has been reported that DEFECTIVE IN EXINE FORMATION1 (DEX1) is essential for exine pattern formation in Arabidopsis thaliana. However, the functions of DEX1 in regulating microspore development are largely not understood. In this study, we show that DEX1 is strongly expressed in the tapetum by using RNA in situ hybridization. dex1 microspores were degenerated and aborted after release from the tetrads. The callose wall in tetrads was thinner in the dex1 mutant than in the wild type, suggesting that DEX1 affects callose formation at the tetrad stage during anther development. RT-PCR and real-time PCR analyses showed that CalS5, which plays an important role in callose synthesis during microspore development, was greatly down-regulated in dex1 plants. DEX1 encodes a membrane protein with one transmembrane domain, one intracellular domain and one extracellular domain. Collectively, our results demonstrate that DEX1 is essential for microspore development, possibly by regulating the expression of CalS5.     

类蝎型吡唑衍生物过渡金属羧酸配合物的合成、结构及热稳定性质

设计并成功合成了2 种新颖的以类蝎型吡唑衍生物为配体的超分子配合物[Co₂(HL¹)₂-(seb)(H₂O)]·2.5H₂O (1)和[Cu(H₂L²)(ox)]·H₂Ox·MeOH (2) (H₂L¹=2,6-二(5-苯基-1H-吡唑-3-基)吡啶, H₂seb=癸二酸, H₂L²=2,6-二(5-甲基-1H-吡唑-3-基)吡啶, H₂Ox=草酸), 并通过元素分析、红外光谱、紫外光谱﹑X 射线粉末衍射(PXRD)和X 射线单晶结构分析对标题配合物进行了表征. 结构分析表明, 在配合物1 和2 中, 配体H₂L¹ 和H₂L² 的配位模式不同, 其中H₂L¹ 以μ₂-η¹-η¹- η¹-η¹ 模式与金属相连, 而H₂L²以μ₁-η¹-η¹-η¹ 的模式与金属相连; 癸二酸和草酸的配位模式也不同, 其中癸二酸作为单齿配体, 草酸作为二齿配体; 配合物1 通过C-H···O,O-H···O, N-H···O 氢键, 形成二维网络层状结构, 而配合物2 通过C-H···O, O-H···O, N-H···O氢键, 形成一维链状结构. 此外还对标题配合物的热稳定性进行了详细的分析.     

一种新颖的Keggin型磷钼酸盐化合物(C10H10N3)3PMo12O40的合成与结构表征

首次合成了一个新的多金属簇化合物，通过元素分析、IR光谱、UV-VIS-NIR反射光谱、ESR谱以及单晶X-射线衍射对其进行了表征，晶体学参数为：三斜晶系，P-1空间群，a=11.5499(17)A，b=12.9776(16)A，c=20.3895(25)A，α=90.72(1)°，β=91.35(1)°，γ=111.43(1)°，V=2843.40(1237)A³，化学组成为(C₁₀H₁₀N₃)₃PMo₁₂O₄₀。Keggin型聚阴离子[PMo₁₂O₄₀]^3-与质子化的2，2′-二吡啶胺之间形成一个三维超分子网状结构。部分质子化的2，2′-二吡啶胺间因π-π作用诱导按Z型链规则排列。将(C₁₀H₁₀N₃)₃PMo₁₂O₄₀应用于电极修饰，在ClO₃^-的电催化还原反应中表现出优良的性能。     

Meteorological conditions of ice accretion based on real-time observation of high voltage transmission line

Meteorological conditions during ice accretion on the 500 kV high voltage transmission lines and test cables are presented, together with a calculation of liquid water content (LWC). The data include meteorological observations and real-time ice accretion on the transmission lines of the central China power grid, from 2008 to 2009 in Hubei Province. Also included are observations of ice thickness, microphysics of fog droplets, and other relevant data from a nearby automated weather station at Enshi radar station, from January to March 2009. Results show that temperature at Zhangen tower #307 was correlated with the temperature at Enshi radar station. The temperature on the surface of the high voltage transmission line was 2-4°C higher than ambient air temperature, although the temperatures were positively correlated. Ice formation temperature was about -2°C and ice shedding temperature was about -2 to -1°C on the high voltage transmission line, both of which were lower than the temperature threshold values on the test cable. Ice thickness was significantly affected by temperature variation when the ice was thin. The calculated LWC was correlated with observed LWC, although the calculated value was greater.     

Rice receptor-like kinase OsSI-RLK2 inhibits internode elongation

Receptor-like kinase participates in the early events of plant signal transduction pathways. Previously, we screened the receptor-like kinase genes in rice and performed phylogenetic analyses. In this study, we isolated a receptor-like kinase gene, OsSI-RLK2, from rice. Expression of OsSI-RLK2 was induced by ABA treatment. In vitro analysis indicates that OsSI-RLK2 has Mn2 dependent autophosphorylation activity, but does not have this activity in the presence of Ca2 and Mg2 . Transgenic rice with over-expressed OsSI-RLK2 displayed shortened internodes resulting in a dwarf phenotype. Taken together, these results suggest that OsSI-RLK2 may represent a new type of functional RLK in rice that can inhibit the elongation of the internode.     

Impacts of external forcing on the 20th century global warming

The impacts of external forcing,including natural and anthropogenic,on the 20th century global warming were assessed with the use of the Grid Atmospheric Model of IAP/LASG Version 1.1.0,fol-lowing the standard coordinated experiment design of the Climate Variability and Predictability(CLIVAR) International Climate of the Twentieth Century Project(C20C) ,Phase II. The results indicate that external forcing plays an important role in the evolution of the land surface air temperature on in-terannual,decadal,and interdecadal time scales,and contributes greatly to the global warming in the following two periods:the early twentieth century between the 1910s and the 1940s and the late twen-tieth century after the 1970s. External forcing also has strong impact on the regional temperature change during the two warming periods except for parts of the Eurasia and the North America conti-nents. In the cooling period,however,the impact of internal variability is dominant.     

一种新型端氨基环磷腈衍生物的合成

以六氯环三磷腈为前体制备了六甘氨酸乙酯取代环三磷腈,然后采用氨基-酯交换法以双氨基化合物乙二胺直接与六甘氨酸乙酯取代环三磷腈反应合成了端氨基环磷腈衍生物。化合物六甘氨酸乙酯取代环三磷腈和端氨基环磷腈衍生物的结构经IR、¹H-NMR和质谱表征。讨论了反应温度、反应时间和投料比对端氨基环磷腈衍生物合成反应的影响,以及六甘氨酸乙酯取代环三磷腈和端氨基环磷腈衍生物后处理过程。该合成方法的反应条件温和,操作简单且收率高达95%。