一种层状化合物的水热合成及其特性

在１００－２５０℃温度范围内,用水热法合成了具有层状结构的化合物Ｌｉ２Ｏ２Ａｌ２Ｏ．ｎＨ２Ｏ．通过Ｘ－射线衍射分析了其结构特征,探索了合成条件对水热扫应产物的影响,用热分析研究了Ｌｉ２Ｏ．２Ａｌ２Ｏ３．ｎＨ２Ｏ的脱水过程,并确定化合物的含水率,用交流复平面阻抗谱测定了化合物在不同温度时的离子电导率,结果表明,用水热法成功地合成了具有较高离子电导率的单相Ｌｉ２Ｏ．２Ａｌ２Ｏ３．ｎＨ２Ｏ２化合物。     

正则Dirichlet形式的正则子空间

正则Dirichlet形式的正则子空间问题,即存在性及其刻画等问题,是作者关注近20年的问题,该问题来自第二作者对于Markov过程的Killing变换的Dirichlet形式刻画问题的研究,这个问题是Dirichlet形式理论的一个基本问题,在最近10年中取得了一点进展.本文将主要叙述问题及其背景,并介绍围绕该问题得到的一些结果与遗留的问题.     

一种基于新的区间二型梯形模糊相似测度的多属性群决策方法

本文首先基于区间二型梯形模糊数的周长、面积、负指数距离提出了一种新的区间二型梯形模糊相似测度,讨论了其性质。其次,基于该相似测度公式分别构建了区间二型梯形模糊专家权重和属性权重确定模型,然后通过集结区间二型梯形模糊决策信息与权重信息,给出了一种基于该相似测度的群决策方法。最后,通过投资方案选择实例说明了该方法的合理性和有效性。     

位移损伤诱发CMOS图像传感器电荷转移损失退化的理论模拟研究

以4T PPD（4个晶体管的钳位光电二极管）型CMOS图像传感器为研究对象，开展注量为1×10¹¹,3×10¹¹,5×10¹¹,7×10¹¹,1×10¹² neutron/cm²的中子辐照下损伤模拟的研究，建立CMOS图像传感器的器件模型和不同注量中子辐照后位移损伤的缺陷模型；采用相关双采样技术测量由亮到暗连续两帧时序脉冲下浮置节点（FD）的输出值，建立测量电荷转移损失（CTI）的模拟方法；获得CTI随中子辐照注量的变化关系，分析CTI随中子累积注量的变化规律，结合中子辐照效应实验验证中子辐照诱发CTI退化的理论模拟计算结果的有效性。研究结果表明，CMOS图像传感器的位移损伤敏感区域为空间电荷区域，中子辐照后会在空间电荷区中引入位移损伤缺陷，这些缺陷通过不断俘获和发射载流子，使信号电荷不能快速转移到FD中，造成电荷转移损失；电荷转移损失随着中子辐照注量的增加而增大，二者在一定范围内呈线性关系。     

Chemical Conversion of a Coumarin Derivative Containing Arylhydrazono: Crystal Structures and Fluorescence Properties

An arylhydrazono-containing coumarin derivative(1) can undergo chemical conversions in two modes. When in the presence of Cu~(2+), a Cu~(2+)-promoted cyclization reaction was observed in aqueous acetonitrile and gives compound 2, while a ring-opening reaction occurs to give compound 3 in the absence of Cu~(2+). Both 2 and 3 were characterized by single-crystal X-ray diffraction. Compound 2 crystallizes in monoclinic C2/c space group with a = 26.606(5), b = 5.8142(12), c = 26.906(5) ?, β = 103.41(3)°, Z = 8, F(000) = 1696, μ = 0.186 mm~(-1), R = 0.0487 and wR = 0.1129. Compound 3 crystallizes in monoclinic P21/n space group with a = 9.917(2), b = 13.644(3), c = 15.912(3) ?, β = 95.38(3)°, Z = 4, F(000) = 896, μ = 0.182 mm~(-1), R = 0.0769 and w R = 0.1617. The spectroscopic studies show that compound 2 exhibits strong fluorescence emission.     

Competition between α-decay and β-decay for heavy and superheavy nuclei

In this work, the β-stable region for Z 90 is proposed based on a successful binding energy formula.The calculated β-stable nuclei in the β-stable region are in good agreement with the ones obtained by Mo¨ller et al. The half-lives of the nuclei close to the β-stable region are calculated and the competition between α-decay andβ-decay is systematically investigated. The calculated half-lives and the suggested decay modes are well in line with the experimental results. The decay modes are mostly β--decay above the β-stable region. Especially for Z 111,all the decay modes are β--decay. Regarding the nuclei above the β-stable region, α-decay and β--decay(α+β-)can occur simultaneously when Z 112. This is a very interesting phenomenon. The competition between α-decay and β-decay is very complex and drastic below the β-stable region. The predictions for half-lives and decay modes of the nuclei with Z =107–110 are presented in detail.     

Effects of chain entanglement on liquid-liquid phase separation behavior of LCST-type polymer blends: Cloud point and decomposition rate

By preparing homogenous blend samples with different degrees of chain entanglement, we report an anomalous contribution of chain entanglement to phase separation temperature and rate of poly(methyl methacrylate)/poly(styrene-comaleic anhydride)(PMMA/SMA) blends presenting a typical lower critical solution temperature(LCST) behavior. The meltmixed PMMA/SMA blends with a higher chain entanglement density present a lower cloud point(Tc) and shorter delay time, but lower phase separation rate at the given temperature than solution-cast ones, suggesting that for the polymer blends with different condensed state structure, thermodynamically more facilitation to phase separation(lower Tc) is not necessarily equivalent to faster kinetics(decomposition rate). The experimental results indicate that the lower Tc of melt-mixed sample is ascribed to smaller concentration fluctuation wavelength(Λm) induced by higher entanglement degree, while higher entanglement degree in melt-mixed sample leads to a confined segmental dynamics and consequently a slower kinetics(decomposition rate) dominated by macromolecular diffusion at a comparable quench depth. These results reveal that the chain packing in polymer blends can remarkably influence the liquid-liquid phase separation behavior, which is a significant difference from decomposition of small molecular mixtures.     

基于本征正交分解的串列叶栅多目标气动优化研究

为提高压气机串列叶栅复杂气动构型优化设计的效率,本文基于本征正交分解(POD)理论,建立了集几何外形参数化、样本空间降维、气动性能求解、降维模型构建和遗传算法寻优于一体的串列叶栅高效优化设计系统,针对叶型型面和叶片相对位置关系参数,开展了多目标优化设计工作。在7°攻角工况下,优化后的串列叶栅的静压升提高了0.53%,总压损失系数下降了9.25%,其他攻角条件下叶栅性能同样也得到了改善。与传统CFD方法相比,极大提高了优化效率,与基于Kriging代理模型相比,本文发展的优化系统由于缩小了设计变量空间,提高了优化的迭代效率,收敛耗时仅为Kriging代理模型的0.0796%。此外,基于POD方法的优化设计系统具有更高的建模精度,使串列叶栅获得了更高的静压升和更低的总压损失系数。优化后的串列叶栅节距系数增大、弯角比减小,减小了掺混损失,抑制了流动分离,改善了全攻角范围内的气动性能。