Effects of CeCl3 on Energy Transfer and Oxygen Evolution in Spinach Photosystem Ⅱ

Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3＋ on energy transfer and oxygen evolution in photosystem Ⅱ （PS Ⅱ ） isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3＋ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ （fluorescence quantum yield） and its oxygen evolving rate were enhanced by Ce^3＋.     

Genetic Algorithms Applied to Li+ Ions Contained in Carbon Nanotubes: An Investigation Using Particle Swarm Optimization and Differential Evolution Along with Molecular Dynamics

Empirical potentials based upon two and three body interactions were applied to the Li⁺-C system, assuming the Li⁺ ions to be distributed inside high-symmetry, single walled carbon nanotubes of different chirality. Structural optimizations for various assemblages were conducted using evolutionary and genetic algorithms, where differential evolution and particle swarm optimization techniques worked satisfactorily. The results were compared with the outcome of some rigorous molecular dynamics simulations. The potential for using the carbon nanotubes in the negative electrode of lithium ion batteries was also critically examined.     

混沌信号在色散光纤传输过程中的演化

研究了色散光纤混沌传输理论及混沌信号与色散光纤相互作用的物理机制;通过耦合激光混沌系统和色散光纤传输信道,提出了色散光纤混沌信号传输演化物理模型;提出混沌信号在色散光纤传输中的非线性演化频率啁啾和公式;着重分析光纤色散对激光混沌信号传输与演化的作用,色散能够展宽混沌信号脉冲,但不影响混沌信号的形状;色散能够改变混沌信号每个频谱分量相位,但不影响混沌信号频谱形状;色散能够改变混沌信号光场慢变场分量的变化,但不改变混沌信号包络时变特性,也不影响混沌信号脉冲的功率分布和场强分布;色散能够改变混沌吸引子在相空间整体旋转角度并使其旋转角度随光纤传输长度而发生改变,但不改变混沌吸引子在相空间中的内部结构.最后数值模拟了混沌信号在光纤传输过程中的相位、场慢变部分分量以及混沌吸引子等演化形式等.     

Development-process-of-nonlinearity-based reliability evaluation of structures

A reliability evaluation approach based on the development process of the structural nonlinearity is presented. The traditional structural system reliability theory for structural safety regarding combination of failure modes is first revisited. It is seen that it stemmed from, and was heavily affected by, the assumption of perfect elasto-plasticity of materials. This will make the number of the failure modes increase in a non-polynomial form against the number of the potential plastic hinges. Moreover, the above methodology does not work appropriately in the case of nonlinearity in general form other than perfect elasto-plasticity, as commonly encountered in engineering practice. Discussions show that total information of the structure is involved in the development process of its nonlinearity, be it a deterministic case or stochastic counterpart. The information needed for reliability evaluation of structures could be extracted, for example, by capturing the probabilistic information of the extreme value of the corresponding response, which could be obtained by using the probability density evolution method. Therefore, the reliability evaluation for structural safety could then be directly evaluated without searching the failure modes. Taking a 10-bar truss as an example, the proposed method is theoretically elaborated and numerically exemplified.     

一种视频目标轮廓跟踪的新算法

对双前沿活动轮廓模型进行了改进，提出一种鲁棒的视频目标轮廓跟踪新方法。通过限制支撑区域的大小，提高了演化速度。拟气球力的引入，既解决了因支撑区域限制导致的均匀区域内演化停滞的问题，又使参数调整更加容易，跟踪更加灵活。能较好地跟踪运动速度变化较大和形变较严重的目标，处理速度较快、并能自动适应目标拓扑的变化，适用于动态背景的视频。实验结果证明了该算法的高效性和鲁棒性。     

企业知识管理中的知识进化

知识进化对企业知识管理(KM)的有效实施意义重大。对企业KM实施中知识进化的意义、内涵以及知识进化机理进行了深入的分析与探讨;提出了知识活性的概念与测度思路。在对知识进化进行分类后,分别阐释了各自的实现机理。在此基础上,重点对编码知识的周期性进化方案与非编码知识进化策略做了深入分析,以期指导企业KM的具体实施过程。     

两种LTE上行SC-OFDMA信号生成方式

首先讨论了Long Term Evolution（LTE）上行传输方案的提出的需求背景,然后简要介绍集中式单载波和分散式单载波概念,研究了它们分别在时域和频域的生成方式,最后分析比较两种方案的优缺点。     

基于最小能量的图像分割算法

文中对图像分割进行了研究,将图像分割过程看成一获取信息的过程,通过最大化此信息量,导出一分割图像的能量泛函,最小化能量泛函即可得到分割结果。在最小化能量函数时,运用最陡梯度下降法导出一曲线进化方程,并用水平集方法来表示此曲线,利用快速水平集方法来进行数值求解。最后的仿真结果表明该算法很有效。     

技术的进步与建筑流派的演进

技术高度发达的21世纪,在应对全球化浪潮,彰显地域特色,抵制"千城一面"的新一轮建筑运动中,作为人性的表达,建筑流派应起到重要作用。在流派与技术此消彼涨的思辩关系上,本文通过对历时性流派理论的梳理分析,认为技术的进步才是健康流派演替发展的深层动因,其实质为一种相互依存关系,是一种技术发展与情感需求的动态平衡。并进一步通过对《北京宪章》相关理论的分析运用,认为只有根植于不同文化背景对新技术的地域化表达是未来形成流派从而彰显地域特色的主要因素。     

冻融疲劳作用下LHFRC损伤演变规律

为了研究层布式混杂纤维混凝土（LHFRC）在冻融疲劳作用下的损伤演变规律，提出了混凝土抗冻劣化的损伤演变数学模型，同时进行了普通混凝土（OC）与层布式混杂纤维混凝土的冻融试验，并在试验的基础上，回归出它们的冻融损伤演变方程。结果表明，LHFRC和OC的初劣点值相同，且在劣化初始阶段具体相同的损伤演变方程；在劣化扩展阶段，LHFRC和OC均具有幂函数形式的损伤演变方程，但LHFRF损伤变量小于同期的OC，钢纤维和聚丙烯纤维有效地抑制了其内部损伤发展。