函数优化的小生境蝙蝠算法

针对蝙蝠算法易陷入局部最优解的缺点,利用小生境技术对蝙蝠算法进行了改进,提出一种小生境蝙蝠优化算法.算法基于小生境技术的适应度共享来分隔种群,引入了小生境排挤机制来保持种群多样性,在延续蝙蝠算法原有并行搜索等优势的基础上,提高了算法的金局搜索能力和局部收敛速度,具有可在不同邻域内发现多个解的特点.通过对一系列经典函数测试,并与已有算法进行比较,结果表明该算法在函数优化问题的求解中具有较高的计算效率和精度,以及较好的全局寻优能力.     

生态学视角下的集装箱海运网络适应度 BA 模型

集装箱海运网络主要反映的是港口与航线的空间组织,其演化是一种复杂的社会、经济、历史的整合过程。运用生态学的隐喻方法对其演化的动力机制进行剖析,充分考虑到现实集装箱海运网络的规模限制与动态发展的演化特征,提出基于“优胜劣汰”的五种机制：节点增加、节点删除、择优连接、反择优删除与重新连接;通过设计港口腹地经济、港口吞吐量、港口区位等适应性指标对港口节点适应度进行度量,构建出一个适应度BA模型;对港口节点度分布的理论推导与数值模拟结果表明：（1）该模型的度分布不仅取决于港口节点的度,更依赖于港口节点的适应度。（2）该模型能够得到一个度分布服从幂律指数为γ＝1＋1／β的无标度网络。（3）若每个港口节点取相同适应度时,该模型呈现出“先到者赢”的特征;若每个港口节点适应度并不完全相同时,该模型呈现出“适者更富”的特征。     

Universal robustness of scale‐free networks against cascading edge failures

Considering the effect of the local topology structure of an edge on cascading failures, we investigate the cascading reaction behaviors on scale‐free networks with respect to small edge‐based initial attacks. Adopt the initial load of an edge ij in a network to be L_ij = (k_ik_j)^α[(∑k_a)(∑k_b)]^β with k_i and k_j being the degrees of the nodes connected by the edge ij, where α and β are tunable parameters, governing the strength of the edge initial load, and Γ_i and Γ_j are the sets of neighboring nodes of i and j, respectively. Our aim is to explore the relationship between some parameters and universal robustness characteristics against cascading failures on scale‐free networks. We find by the theoretical analysis that the Baraba'si‐Albert (BA) scale‐free networks can reach the strongest robustness level against cascading failures when α + β = 1, where the robustness is quantified by a transition from normal state to collapse. And the network robustness has a positive correlation with the average degree. We furthermore confirm by the numerical simulations these results.     

γ-氨基丁酸和苯甲酸共晶体及其形成条件的振动光谱分析

使用太赫兹时域光谱(THz-TDS)、傅里叶红外光谱(FTIR)和傅里叶拉曼光谱(FT-Raman)技术在室温下对γ-氨基丁酸(GABA)、苯甲酸(BA)及其研磨和溶剂共晶体进行表征分析。FTIR,FT-Raman及THz光谱都能够分辨原料物质及GABA-BA共晶体。其中THz实验结果显示了GABA-BA研磨和溶剂共晶体位于0.93,1.33,1.57THz的吸收峰明显区别于原料物质,这体现了不同物质在THz波段具有明显的指纹特征。为确认GABA-BA共晶体的晶型结构,分别采用FTIR和FT-Raman光谱进行光谱归属。通过FTIR的光谱归属推断GABA-BA共晶体由GABA中的氨基H_23和BA中的羰基O1构成第一个氢键,氨基中的N18结合BA中的羟基H15形成第二个氢键。FT-Raman光谱中,原料物质GABA中位于576,886,1 250,1 283,1 337,1 423和1 470cm~(-1)处归属于—CH_2,—NH_2弯曲振动的Raman散射峰在GABA-BA共晶体内消失,判定GABA中的氮原子N18亦可作为氢键受体,从而验证了GABA-BA共晶体的晶型结构。此外,为了进一步说明溶剂pH值对GABA-BA共晶体的形成条件的影响,利用THz-TDS,FT-Raman光谱确认了该共晶体在溶剂条件2.00≤pH≤7.20可稳定地生成。这一研究结果同时也为利用THz-TDS,FTRaman光谱技术辨别固体物质晶型结构、晶型形成条件提供了实验及理论依据。     

一类变幂率的无标度网络模型构建和分析

依据网络中节点的局域特征,提出了一种简单的节点重要性的度量方法.其主要原则是网络中节点的重要性不但与节点本身的度具有一定的关系,而且与节点的邻居节点的度也存在一定的关联.实验结果表明:该方法能够在不了解网络全局拓扑架构的基础上,比较细致地描述网络中各节点之间的差异性,而且算法时间复杂度仅为o(m+n),因此对于大型复杂网络也可以获得理想的计算能力.     

液下原子力显微镜对BA膜和C60复合LB膜的重组

利用Langmuir-Blodgett (LB)方法, 以二十二酸 (behenic acid, BA)、 二十酸(arachic acid, AA)、 十八酸 (stearic acid, SA) 和十八胺 (octadecanyl amine, OA)作为辅助成膜材料, 组装了C₆₀复合膜和BA膜, 液下原子力显微镜直接对LB膜在水相中的重组进行观察. 结果表明, C₆₀复合LB膜和二十二酸镉单层膜在水相中都发生了重组, 但前者的重组程度较小, 并且C₆₀聚集体颗粒的粒径均匀. 脂链的重组可能是由于水相中的Cd²⁺减弱了头基与云母基片之间的相互作用引起的, 相同条件下由于混合C₆₀膜中发生酸碱缔合使其重组程度较小.     

sd-IBA跟sdg-IBA以及IBA-Ⅰ跟IBA-Ⅱ的关系

通常容易将sd-IBA 和sdg-IBA 的关系理解成只须将后者有关g 的项弃去就得到前者.和此类似容易认为在IBA--Ⅱ中的质子和中子的区别被忽视以后就会简化成IBA-Ⅰ.实际上这类想法是没有根据的,至多也不过是一种粗略的近似.上述各种关系应该从群表示的特点米看,sd 和sdg 理论属于不同的群链,IBA-Ⅰ和IBA-Ⅱ的关系也是如此.     

Recent developments in manufacturing emulsions and particulate products using membranes

Membrane emulsification (ME) is a relatively new technique for the highly controlled production of particulates. This review focuses on the recent developments in this area, ranging from the production of simple oil-in-water (O/W) or water-in-oil (W/O) emulsions to multiple emulsions of different types, solid-in-oil-in-water (S/O/W) dispersions, coherent solids (silica particles, solid lipid microspheres, solder metal powder) and structured solids (solid lipid microcarriers, gel microbeads, polymeric microspheres, core-shell microcapsules and hollow polymeric microparticles). Other emerging technologies that extend the capabilities into different membrane materials and operation methods (such as rotating membranes, repeated membrane extrusion of coarsely pre-emulsified feeds) are introduced. The results of experimental work carried out by cited researchers in the field together with those of the current authors are presented in a tabular form in a rigorous and systematic manner. These demonstrate a wide range of products that can be manufactured using different membrane approaches. Opportunities for creation of new and novel entities are highlighted for low throughput applications (medical diagnostics, healthcare) and for large-scale productions (consumer and personal products).     

Wavelength-ratiometric near-physiological pH sensors based on 6-aminoquinolinium boronic acid probes

We describe the pH response of a set of isomeric water-soluble fluorescent probes based on both the 6-aminoquinolinium and boronic acid moieties. These probes show spectral shifts and intensity changes with pH, in a wavelength-ratiometric and colorimetric manner. Subsequently, changes in pH can readily be determined around the physiological level.Although boronic acid containing probes are known to exhibit pH sensitivity along with an ability for saccharide binding/chelating, the new probes reported here are considered to be unique and show an unperturbed pH response, even in the presence of high concentrations of background saccharide, such as with glucose and fructose, allowing for the predominant pH sensitivity. The response of the probes is based on the ability of the boronic acid group to interact with strong bases like OH⁻, changing from the neutral form of the boronic acid group, R-B(OH)₂, to the anionic ester, R-B⁻(OH)₃, form, which is an electron donating group. The presence of an electron deficient quaternary heterocyclic nitrogen center and a strong electron donating amino group in the 6-position of the quinolinium backbone, provides for the spectral changes observed upon OH⁻ complexation. In addition, by comparing the results obtained with systems separately incorporating 6-methoxy or 6-methyl substituents, the suppressed response towards monosaccharides, such as with glucose and fructose, can clearly be observed for these systems. Finally we compare our results to those of a control compound, BAQ, which does not contain the boronic acid group, allowing a rationale of the spectral changes to be made.