1.3 GHz超导腔磁通排出效应研究

设计并搭建了一套高精度的磁场测量和补偿系统,并结合中国科学院高能物理研究所(IHEP)的2K超导腔垂直测试平台对1.3 GHz单加速间隙超导腔的磁通排出效应开展了实验研究:利用研制的磁场测量和补偿系统能够精密地测量超导腔赤道位置磁场,并能够将磁场补偿至小于5.0×10-8 T;并对超导腔不同表面温度梯度下的磁通排出效应进行了测量分析;对钉扎了磁场的超导腔进行了射频性能测试,研究了超导腔电阻对磁通钉扎的敏感度,以及在不同电场梯度下超导腔的表面电阻变化情况。结果表明,研制的高精度磁场测量和补偿系统能够满足超导腔磁通排出研究的需求;高的超导腔表面温度梯度有利于磁通的排出;磁通钉扎电阻的敏感度随着加速电场梯度的增加而增大,导致超导腔的性能下降。此实验研究也为后续超导腔的研制奠定了一定基础。     

Palladium nanoparticles stabilized by phosphine ligand for aqueous phase room temperature suzuki-Miyaura coupling

Water soluble phosphine ligand triphenylphosphine-3,3′,3″-trisulfonic acid trisodium salt (TPPTS) was used as the stabilizer as well as the activator to the palladium nanoparticles, which showed a high catalytic performance for aqueous phase Suzuki-Miyaura coupling reaction at room temperature.     

砖砌烟囱爆破拆除倾倒过程的观测分析

本文通过对砖砌烟囱爆破拆除的实例分析得到,在砖砌烟囱的爆破拆除倾倒过程中,其倾倒支点是不断移动的,随着烟囱主体的不断下沉,相对于未垮部分的烟囱主体来说,该支点沿烟囱筒体不断向上移动。这表明,不能简单地按刚体模型描述砖砌烟囱的倾倒运动。     

Simultaneous determination of cinnamaldehyde and its metabolite in rat tissues by gas chromatography–mass spectrometry

Cinnamaldehyde (CA), an active ingredient isolated from the traditional Chinese medicine Cortex Cinnamomi, has a wide range of bioactivities. To clarify the distribution characteristics of CA, a selective and sensitive method utilizing gas chromatography–mass spetrometry was initially developed for simultaneously determining the concentration of CA and its metabolite cinnamyl alcohol in rat tissues. Selected ion masses of m/z 131, 105 and 92 were chosen, and separation of the analytes was performed on a DB‐5 ms (30 m × 0.25 mm, 0.25 µm, thickness) capillary column by gas chromatography–mass spectrometry. The calibration curves demonstrated good linearity and reproducibility over the range of 20–2000 and 20–4000 ng/mL for various tissue samples. Recoveries ranged from 86.8 to 107.5%, while intra‐ and interday relative standard deviations were all <11.3%. The analysis method was successfully applied in tissue distribution studies for CA and cinnamyl alcohol. As CA and cinnamyl alcohol may inter‐convert to one another, simultaneous determination of both analytes provides a comparative and accurate data for tissue study. The concentrations of CA and cinnamyl alcohol remaining in spleen were the highest among the main organs, including heart, liver, spleen, lung, kidney and brain. In addition, there was no long‐term accumulation of CA in rat tissues. Copyright © 2014 John Wiley & Sons, Ltd.     

基于集群的高频合成孔径声纳并行处理方法

大测绘带下的高频合成孔径声纳需要解决的主要问题是海量数据的实时处理。该问题对数据处理的计算平台、成像处理和架构提出了很高的要求。本文利用非均匀离散快速傅里叶变换改进了成像算法,使之能够适应采用了多子阵技术的合成孔径声纳;提出了高频合成孔径声纳信号并行处理方法,在集群上实施了该方法,并进行了湖试试验。实时成像结果表明,改进的并行处理方法可以满足分辨率为距离向4cm、方位向5 cm,测绘带宽为200m的高频合成孔径声纳实时成像要求,具有较高的稳定性。     

On the Uniform Nonsingularity Property for Linear Transformations on Euclidean Jordan Algebras

In a recent paper, Chua and Yi introduced the so-called uniform nonsingularity property for a nonlinear transformation on a Euclidean Jordan algebra and showed that it implies the global uniqueness property in the context of symmetric cone complementarity problems. In a related paper, Chua, Lin, and Yi raise the question of converse. In this paper, we show that, for linear transformations, the uniform nonsingularity property is inherited by principal subtransformations and, on simple algebras, it is invariant under the action of cone automorphisms. Based on these results, we answer the question of Chua, Lin, and Yi in the negative.     

A comparative study on the morphology of P3HT:PCBM solar cells with the addition of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles by spin and rod coating methods

Our previous study presented up to 20% power conversion efficiency (PCE) enhancement of poly(3-hexylthiophene):phenyl-C₆₁-butyric acid methyl ester (P3HT:PCBM) solar cells under the Fe₃O₄ nanoparticles (NPs) self-assembly (SA) effect by spin coating. Fe₃O₄ NPs (about 11 nm hydrodynamic diameter) form a thin layer at the top interface of the light absorbing active layer, which results in the generation of PCBM rich region improving the charge transport (Zhang et al. Sol Energ Mat Sol C 160:126–133, 2017). In order to investigate the feasibility of this Fe₃O₄ NPs SA effect under large-scale production condition, a smooth rod was implemented to mimic roll-to-roll coating technique and yield active layers having about the same thickness as the spin-coated ones. Small angle neutron scattering and grazing incidence X-ray diffraction were employed finding out similar morphologies of the active layers by these two coating techniques. However, rod-coated solar cell’s PCE decreases with the addition of Fe₃O₄ NPs compared with the one without them. This is because PCBM rich region is not created at the top interface of the active layer due to the absence of Fe₃O₄ NPs, which is attributed to the weak convective flow and low diffusion rate. Moreover, in the rod-coated solar cells, the presence of Fe₃O₄ NPs causes decrease in P3HT crystallinity, thus the charge transport and the device performance. Our study confirms the role of spin coating in the Fe₃O₄ NPs SA effect and enables researchers to explore this finding in other polymer nanocomposite systems.     

A multifunctional silicotungstic acid-modified Li-rich manganese-based cathode material with excellent electrochemical properties

Journal of Solid State Electrochemistry - Li-rich layered oxide (LrLO) cathode has attracted much attention for Li-ion batteries in recent years due to its superior capacity of exceeding...     

用多子阵空间互相关矩阵估计合成孔径声呐基阵速度

受接收子阵长度的影响,单纯依靠重叠相位中心的合成孔径声呐(Synthetic Aperture Sonar,SAS)基阵速度估计方法的精度较低。为此,提出一种利用多子阵空间互相关矩阵的方法以提高速度估计精度。通过SAS多子阵回波数据构造空间互相关矩阵(Spatial Mutual Correlation Matrix,SMCM),利用Radon变换和SMCM系数分布精确估计重叠相位中心对直线(Line of Displaced Phase Center Pairs,LDPCP)参数,并利用重叠相位中心对速度关系式估计SAS基阵速度。对高低频SAS试验数据应用的结果表明:该方法可有效地消除接收子阵长度的影响,将基阵速度估计的精度提高3~5倍,满足高频和低频SAS系统成像的要求。