Catalytic epoxidation of olefin over supramolecular compounds of molybdenum oxide clusters and a copper complex

The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.

Cluster exponential synchronization of a class of complex networks with hybrid coupling and time-varying delay

This paper deals with the cluster exponential synchronization of a class ot complex networks wlm nyorm coupm^g and time-varying delay. Through constructing an appropriate Lyapunov-Krasovskii functional and applying the theory of the Kronecker product of matrices and the linear matrix inequality （LMI） technique, several novel sufficient conditions for cluster exponential synchronization are obtained. These cluster exponential synchronization conditions adopt the bounds of both time delay and its derivative, which are less conservative. Finally, the numerical simulations are performed to show the effectiveness of the theoretical results.

Cluster synchronization of uncertain complex networks with desynchronizing impulse

Cluster synchronization of nonlinear uncertain complex networks with desynchronizing impulse is explored. First of all, a feedback controller is employed, based on the Lyapunov stability theorem and Lipschitz condition, to guarantee that the uncertain complex networks with desynchronizing impulse synchronize with an object trajectory. Furthermore, a synchronizing impulse controller is presented, which is more efficiently and directly used to achieve the cluster synchronization. Finally, numerical examples are examined to show the effectiveness of the proposed methods.

Electron Spin Resonance(ESR)Spectroscopy of the Transition-metal Complexes and Clusters I.Systematic Investigations of Real-and Complex-Orbital Methods for Calculating the d-Orbital Energies of a Low-spin(S=1/2)nd^5(t_2~5,~2T_2)(n=3

On the basis of the first paper’s theoretical derivations and concrete instance calculations of the energies of the d orbitals for a low spin ( S =1/2) nd 5(t 2 5, 2T 2)(n =3, 4, 5) system, the major results reported in this paper contain the following two respects: explicit relationships between the coefficients of the real and complex Kramers doublets have been derived by using two types of the expressions of the principal components of the g tensors in real and complex orbital representations obtained in the first paper; the use of these relationships of the real and complex orbital coefficients has carried out a series of mathematical demonstrations on the agreement of the real and complex orbital methods .

Molecular Design and Electronic Structure of Polynuclear Rare Earth Complexes and Clusters

Studies on the electronic structure,molecular design,syntheses of some novel series of tetranuclear rare earth complexes in our laboratory have been reviewed.Spin-unrestricted localized INDO method was used to calculate the electronic structure and the chemical bonding in the typical rare earth cluster Sc[Sc_6Cl_(12)Co]was discussed.

Synthesis,Structure and Electrochemistry of Triruthenium Cluster Complex [Ru_3(μ_3- O)(μ-CH_3CO_2)_6(py)_2(PPh_2py)](PF_6)·CH_2Cl_2

The reaction between [Ru3(3-O)(-CH3CO2)6(py)2(MeOH)](PF6) (py = pyri- dine) and diphenyl-2-pyridyl-phosphine (PPh2py) gave the triruthenium cluster complex [RuIII3(3-O)(-CH3CO2)6(py)2(PPh2py)](PF6)CH2Cl2 (C40H44Cl2F6N34O13P2Ru3) which was characterized by elemental analysis, IR, UV-Vis and 31P NMR spectroscopy, and X-ray single- crystal diffraction. The structure is of monoclinic, space group P21/n with a = 16.3896(1), b = 16.8773(2), c = 19.1438(2) ? b = 95.888(1), V = 5267.47(9) ?, Mr = 1324.83, Dc = 1.671 g/cm3, F(000) = 2636, m = 1.092 mm-1 and Z = 4. The final refinement gave R = 0.0508 and wR = 0.1111 for 6987 observed reflections (I > 2s(I)). Three Ru(III) atoms bridged by m3-oxo donor form an approximately isosceles triangle. The complex shows three quasireversible one- electron processes at E1/2 = 1.22 +0.03 and 1.20 V vs. Ag/AgCl.

A study of TCM master Yan Zhenghua’s medication rule in prescriptions for digestive system diseases based on Apriori and complex system entropy cluster

Objective:To explore Yan Zhenghua’s drug selection rule for treating digestive system diseases using data mining.Methods:The 609 medical records of digestive system diseases treated by Yan Zhenghua were collected and the herbs in these recipes were examined using a data mining technique.The correlativity between herb pairs and association rules was studied using an Apriori algorithm and the correlativity among multi-herbs was studied using a complex system entropy cluster technique.Results:Yan Zhenghua’s treatment of digestive system diseases featured 15 herbs prescribed at least 159 times each,22 herb pairs prescribed at least 155 times each,and eight frequently used herb core combinations.A confidence greater than 0.91 and a support level greater than 20%were achieved using the modified mutual information method.Conclusion:The data mining results conformed to findings from clinical practice.The data mining method is a valuable technique with which to study the experience of famous,elderly traditional Chinese medicine physicians.

Hierarchical Modeling by Recursive Unsupervised Spectral Clustering and Network Extended Importance Measures to Analyze the Reliability Characteristics of Complex Network Systems

The complexity of large-scale network systems made of a large number of nonlinearly interconnected components is a restrictive facet for their modeling and analysis. In this paper, we propose a framework of hierarchical modeling of a complex network system, based on a recursive unsupervised spectral clustering method. The hierarchical model serves the purpose of facilitating the management of complexity in the analysis of real-world critical infrastructures. We exemplify this by referring to the reliability analysis of the 380 kV Italian Power Transmission Network (IPTN). In this work of analysis, the classical component Importance Measures (IMs) of reliability theory have been extended to render them compatible and applicable to a complex distributed network system. By utilizing these extended IMs, the reliability properties of the IPTN system can be evaluated in the framework of the hierarchical system model, with the aim of providing risk managers with information on the risk/safety significance of system structures and components.

Cluster projective synchronization of complex networks with nonidentical dynamical nodes

We investigate a new cluster projective synchronization （CPS） scheme in time-varying delay coupled complex dynamical networks with nonidentical nodes. Based on the community structure of the networks, the controllers are designed differently for the nodes in one community, which have direct connections to the nodes in the other communities and the nodes without direct connections to the nodes in the other communities. Some sufficient criteria are derived to ensure the nodes in the same group projectively synchronize and there is also projective synchronization between nodes in different groups. Particularly, the weight configuration matrix is not assumed to be symmetric or irreducible. The numerical simulations are performed to verify the effectiveness of the theoretical results.

Novel Properties of Supramolecular Complexes Formed by Pairing Cationic Porphyrin and Anionic Metal-Oxo Cluster

MTBPyP (meso-tetrakis(4-N-benzylpyridyl)porphyrin, M=H-2, Zn) bearing positive charge has been shown to associate with SiW12O404- in water solution. The spectral evolution and Job's plots analyses reveal that the relatively stable aggregates contain equal numbers of MTBPyP4(+) and SiW12O404-.

Coarse-Graining Method Based on Hierarchical Clustering on Complex Networks

With the rapid development of big data, the scale of realistic networks is increasing continually. In order to reduce the network scale, some coarse-graining methods are proposed to transform large-scale networks into mesoscale networks. In this paper, a new coarse-graining method based on hierarchical clustering (HCCG) on complex networks is proposed. The network nodes are grouped by using the hierarchical clustering method, then updating the weights of edges between clusters extract the coarse-grained networks. A large number of simulation experiments on several typical complex networks show that the HCCG method can effectively reduce the network scale, meanwhile maintaining the synchronizability of the original network well. Furthermore, this method is more suitable for these networks with obvious clustering structure, and we can choose freely the size of the coarse-grained networks in the proposed method.

中国省会航空节点城市复杂时空系统协调度变化及空间特征分析

航空运输业提升了城市系统的吸引力并激发新的交通需求,引导城市经济和空间结构快速演进。本文构建了包含经济、规模、外贸、科技、社会、环境、航空等要素在内的城市复杂时空系统指标体系,对中国省会航空节点城市及其构成的7个空管区的复杂时空系统发展的协调程度变化情况及时空聚类特征、空间溢出效应进行了分析。研究发现:2001—2019年,中国31个省会(首府、直辖市)航空节点城市在复杂时空系统发展过程中呈现了或分散、或集中的趋势特征,南方城市在研究末期的协调程度表现更好。7个空管区中,华北区协调度最高,新疆区、西北区、华东区、中南区的协调度水平发展增速较快,航空系统的平均协调度最高。各航空节点城市复杂时空系统协调度的时空聚类模式存在空间分异特征与聚类特征,航空系统在空管区的聚类优势最为突出,经济系统在空管区聚类辐射范围最大。航空、规模、科技与环境系统均表现了正向直接空间溢出效应,经济与科技系统表现了正向间接空间溢出效应。通过全面分析航空节点城市及空管区的复杂时空系统协调度变化,精准判定了航空节点城市多指标系统在区域发展过程中的影响程度及时空分布异质性,对拓展航空地理研究及促进航空节点城市高质量综合发展提供理论依据。

基于复杂网络的江苏海洋工程装备产业集群结构实证研究

产业集群具有大规模复杂网络的结构特征,因此基于复杂网络视角研究海工装备产业集群结构特征,进而构建江苏省海洋工程装备产业集群复杂网络拓扑图。通过对复杂网络度分布、平均路径长度、聚集系数、网络密度进行统计分析后发现:海工装备产业集群网络结构尚处于快速成长期,BA无标度网络特性初步显现;同时,网络演化过程还存在着集群网络结构不稳定、不完善、不成熟等问题。要促进江苏海工产业集群发展,就应该优化集群产业结构,构建完整的江苏海工产业链,提高海工集群资源整合能力。

成渝机场群航线网络有向加权结构特征分析

成渝机场群是成渝地区双城经济圈建设的重大战略部署,为探索成渝机场群航线网络拓扑结构的复杂性,运用复杂网络理论构建有向加权航线网络模型,计算其航线网络基本统计指标、中心性指标以及网络效率并对其网络结构进行分析研究。结果表明成渝机场群具有明显的小世界特性;天府与江北机场为机场群实际枢纽,但航线同质化竞争严重,航点重合度较高问题较为严重;各支线机场虽具备一定缓解枢纽压力但层次结构不清晰及发展滞缓;枢纽与非枢纽间联系不紧密、中心化程度低;达州与巫山机场可分别作为枢纽的紧密次枢纽机场进行发展;当网络收到攻击时网络效率低下,并提出参考建议。

八核铁簇化合物的制备、表征及其对高氯酸铵的热分解催化

以5,5′-{[3,3′-双(1,2,4-噁二唑)]-5,5′-基}-双(1-羟基四唑)为配体,通过溶剂热法制备了一种新型含能铁簇化合物[Fe_(2)Ⅲ(μ2-CH_(3)O)(μ_(3)-OH)(μ_(2)-O)(BODTO^(2-))(H_(2)O)]4(1),并对其进行了单晶X-射线衍射、差示扫描量热和热重分析等表征,分析了其结构和热稳定性,同时通过差热分析仪研究了化合物1对高氯酸铵(AP)热分解的催化性能。测试结果表明,化合物1为立方晶系I-43d空间群,密度为1.506 g·cm^(-3);晶体结构中Fe^(3+)与Fe^(3+)通过氧原子桥联,形成笼状结构;热分解峰值温度为513.9,617.6 K和669.4 K;爆速为6.94 km·s^(-1),爆压为19.09 GPa;撞击感度为15 J,摩擦感度为360 N。当添加质量分数为10%的化合物1时,AP的高温分解温度降低65 K,活化能降低82.2 kJ·mol^(-1),证实该铁簇化合物对AP的热分解具有较好的催化活性,具有应用于含能燃烧催化剂的潜质。

复杂交汇水域船舶航路网提取方法研究

文中提出了一种适用于复杂交汇水域船舶航路网的提取方法.采用轨迹聚类算法获取水域主要船舶交通流,通过水域栅格化将各船舶交通流转化为栅格图像,运用图像细化的原理从不同交通流中提取对应船舶航路,以距离阈值为标准识别航路之间的交汇点,最终形成水域船舶航路网.结果表明:该方法不仅可有效提取水域内主要船舶航路以及航路交汇点,还可同时获取交汇点密集区域.

基于网约车数据的级联城市区域分析框架研究

针对城市区域的复杂性和多变性,提出了一个级联城市区域分析框架(cascaded urban area analysis framework,CUAAF),用来对城市区域进行时空聚类分析.首先,将城市区域划分为多个地理栅格.其次,采用新的区域时空行为指标(areabehaviorindex,ABI)评估任意2个栅格之间的相关性.接着,用Louvain算法对相应的栅格网络进行分析,得到聚类区域.在得到聚类区域后,可再次将该区域输入CUAAF框架,进行级联分析,得到更多分层信息.级联实验可以采用多种指标分析城市区域,从不同层次了解城市区域,获得更详细的城市区域信息.最后,分别用周中周末的数据做了对比实验,结果显示本文方法具有稳健性和数据敏感性.

基于生态系统服务功能价值簇的复合型产业模式设计——以河北省阜平县为例

[目的]基于土地利用多功能特性构建复合型产业模式,为提高山区县的土地利用效率,推进区域生态与经济的高质量发展提供方法和参考。[方法]以太行山中段的阜平县为例,选取水源供给、保持土壤等9类生态系统服务功能作为评判阜平县土地多种功能空间集聚特征的依据,通过空间聚类分析得到不同的功能价值簇,并调整形成生态系统服务主导功能价值分区;在此基础上,叠加土地利用现状、地形地貌和现有产业发展布局,构建复合型产业发展模式。[结果](1)将研究区按生态系统服务功能价值的空间集聚特征分为6种功能价值簇;(2)调整各簇边界,形成维持生物多样性+提供美学景观+保持土壤区、提供美学景观+水源供给+原材料生产区等6类生态系统服务主导功能价值区;(3)在生态系统服务主导功能价值区的基础上,设计出“旅游业+文化产业”“智慧农业+旅游业”等7种复合型产业发展模式,可为实现阜平县乡村振兴与高质量发展提供新的驱动力。[结论]复合型产业模式的设计能够实现生态保护与经济发展的双驱并进,可为解决山区县生态保护与经济发展的矛盾问题提供案例参考。

紫花苜蓿复合体(Medicago sativa complex)叶片形态特征及数量分类研究

运用比较形态学和比较解剖学方法,使用扫描电镜和光学显微镜对紫花苜蓿复合体（Medicago sativa complex）6个分类群的叶片形态特征和叶片解剖结构进行了观察和比较,并以15个叶片表征形态性状为基础,采用聚类分析法（UPGMA）和主成分分析方法（PCA）对6个分类群进行了数量分类研究。观察结果表明：各分类群叶片的上、下表皮多为不规则形细胞;垂周壁呈深浅不一的波状;气孔器为不规则型,具有蜡质气孔盖,气孔密度有一定差异。6个分类群的叶片均为薄纸质型,厚度130~170μm,表皮细胞切面近圆形或近长方形;栅栏组织细胞1~2层,厚度41~68μm,细胞排列紧密;海绵组织厚度32~75μm,细胞排列疏松;不同分类群叶片的组织疏松度和组织紧缩度有一定的差异,大花苜蓿（M.trautvetterii Sumnev.）叶片的组织疏松度最高,紫花苜蓿叶片的组织紧缩度最高。UPGMA结果显示：在结合线1.53处可将6个分类群划分为2支,其中,黄花苜蓿（M.falcataL.）独立为一支,其余5个分类群聚成另一支;在结合线1.18处,第2支又被分成2个亚支,其中一个亚支包含紫花苜蓿和天山苜蓿（M.tianschanica Vassilcz.）,另一个亚支则包含西锡金苜蓿（M.schischkinii Sumnev.）、座垫苜蓿（M.rivularis Vassilcz.）和大花苜蓿。PCA结果表明：对紫花苜蓿复合体而言,叶片表皮细胞形状、垂周壁式样、轴性分化特征、组织疏松度和气孔密度等特征具有较好的分类价值;基于主成分分析的Q分布图与聚类分析结果也具有较高的一致性。根据本研究结果及前人的研究结果,认为国产的紫花苜蓿复合体应包含3个分类群,即紫花苜蓿、黄花苜蓿及多变苜蓿（M.varia Martyn）。此外,西锡金苜蓿、座垫苜蓿、天山苜蓿和大花苜蓿等杂交后代分类群的性状分化不稳定,应属于多变苜蓿的同种异名植物。

基于郊狼优化算法的扇区管制复杂性聚类与仿真验证

为提高科学评估扇区管制复杂性的能力,本文提出基于郊狼优化算法(COA,coyote optimization algorithm)的扇区管制复杂性聚类算法。首先,引入逐维变异改进策略来改进郊狼优化聚类算法,解决其易陷入局部最优解的问题。其次,以中国西北地区区域管制扇区为研究对象,采用改进郊狼优化聚类算法(ICOCA,improved coyote optimization clustering algorithm)对扇区管制复杂性指标进行聚类分析。最后,对扇区聚类结果进行仿真验证,结果证明了所提算法在扇区管制复杂性分类方面的有效性和可靠性,可为后续的空域管理提供有效的数据决策。