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Chiral Ag nanowires (CAgNWs), fabricated inside chiral carbon nanotubes (CCNTs), exhibit strong circular dichroism (CD) signals in the visible and near-IR regions. Enantiopure CCNTs were prepared by carbonization of the self-assembled chiral polypyrrole nanotubes according to our previous report. Ag ions could be easily introduced into the chiral pores of CCNTs due to the capillary phenomenon. After hydrogen reduction, the optically active CAgNWs formed inside the channels of the CCNTs. The helical channels in the CCNTs played a predominant effect on the chiral formation of the CAgNWs. This system provides new insight into the fabrication as well as the study of optical activity (OA) of chiral inorganic nanomaterials. Such novel chiral inorganic material will bring new opportunities in non-linear optics, biosensors and chiral recognition.

A macroporous silica with azimuthally shifted double-diamond frameworks has been synthesized by the self-assembly of an amphiphilic ABC triblock terpolymer poly(tert-butyl acrylate)-b-polystyrene-b-poly(ethylene oxide) and silica source in a mixture of tetrahydrofuran and water. The structure of the macroporous silica consists of a porous system separated by two sets of hollow double-diamond frameworks shifted 0.25c along ⟨001⟩ and adhered to each other crystallographically due to the loss of the mutual support in the unique synthesis, forming a tetragonal structure (space group I41/amd). The unit cell parameter was changed from a = 168 to ∼240 nm with c = √2a by tuning the synthesis condition and the wide edge of the macropore size was ∼100 to ∼140 nm. Electron crystallography was applied to solve the structure. Our studies demonstrate electron crystallography is the only way to solve the complex structure in such length scale. Besides, this structure exhibits structural color that ranged from violet to ...

The biomimetic synthesis of relevant silica materials using biological macromolecules as templates via silica biomineralization processes attract rapidly rising attention toward natural and artificial materials. Biomimetic synthesis studies are useful for improving the understanding of the formation mechanism of the hierarchical structures found in living organisms (such as diatoms and sponges) and for promoting significant developments in the biotechnology, nanotechnology and materials chemistry fields. Chirality is a ubiquitous phenomenon in nature and is an inherent feature of biomolecular components in organisms. Helical biomolecules, one of the most important types of chiral macromolecules, can self-assemble into multiple liquid-crystal structures and be used as biotemplates for silica biomineralization, which renders them particularly useful for fabricating complex silica materials under ambient conditions. Over the past two decades, many new silica materials with hierarchical structures and complex morphologies have been created using helical biomolecules. In this review, the developments in this field are described and the recent progress in silica biomineralization templating using several classes of helical biomolecules, including DNA, polypeptides, cellulose and rod-like viruses is summarized. Particular focus is placed on the formation mechanism of biomolecule-silica materials (BSMs) with hierarchical structures. Finally, current research challenges and future developments are discussed in the conclusion.

The city road system, as well as other complex systems, can be modeled as networks. Studies investigating the relationship between network structure and functionality provide a novel perspective to investigate the robustness of a city road network by analyzing its structure. The fact that different events may lead to different levels of traffic interruption requires that the investigation on the robustness of city road networks be conducted at multiple granularities. In this study, road networks are modeled at three different granularities: segment-based, stroke-based and community-based model to investigate the response of road networks under punctiform, linear and zonal traffic interruptions respectively. An empirical study with six city road networks around the world shows that the topological structure, especially the diversity level in the betweenness centrality distribution of the network, is more essential to the robustness of the city road network than geographical features and inherent attributes. The performances of city road networks under attacks are consistent in different cities due to the similarity in their topological structures but differ by granularity because city road networks modeled at different granularities have different topological structures. This variation illustrates that the robustness analysis of city road networks should be modeled at the appropriate granularity for a given traffic situation. Furthermore, empirical results suggest that the tolerance threshold for urban traffic is the critical point where the city road network begins to split into several components. The robustness analysis solution proposed in this article can identify these critical points to provide an early warning in urban traffic interruptions.

That combining membrane computing with optimization technology offers a new information interaction model for the research of problems in optimization filed. Based on this, a membrane algorithm owned six basic membranes is proposed to solve the defects of the slow convergence and the small diversity in solving vehicle routing problem with time window. In order to further improve the efficiency and the precision, some new rules are designed: for the former problem, a node classifier is introduced to improve the efficiency by filtering directly a plenty of in-feasible solutions; two methods for the latter problems: an uncertain segment crossover is designed in the corresponding membrane in order to explore directly two feasible segments and segment-node insertion operation is introduced in order to make two individuals inserted synchronously another path. In order to verify the effectiveness of the algorithm, a series of experiments are designed. Known through the results of experiments that these two properties of membranes make the search ability of the algorithm improving quickly for local and global exploration and node classifier improves effectively the running efficiency of this algorithm, which proves that membrane algorithm can accelerate the convergence speed and increase diversity of population.

Chiroptical properties of pure inorganic material have been achieved by dispersing small amounts of achiral Ag nanoparticles into highly ordered chiral mesoporous silica. There are three types of chirality in chiral mesoporous silica: i) the helical hexagonal surface, ii) the helical pore orientation, and iii) the helical arrangement of aminopropyl groups on the surface of the mesopores, all of which impart plasmonic circular dichroism and have been investigated by introducing Ag nanoparticles into the as-made, calcined and extracted chiral mesoporous silica, respectively. The three types of optical response originate from asymmetric plasmon-plasmon interactions of achiral Ag nanoparticles in three types of chiral environments. Among the three sources of chirality, the helical pore orientation was considered to be predominantly responsible for the optical response owing to the high efficiency of nanoscale chirality. Interestingly, large Ag nanoparticles aggregation as a result of calcination still resulted in a strong optical activity, even the chiral mesostructure was destroyed completely. Rather than the pitch length, the length of helical channel was more effective for increasing the intensity of plasmonic circular dichroism due to longitudinal propagation of Ag nanoparticles along helical channel. Such novel chiral inorganic material will bring new opportunities in non-linear optics, biosensors and chiral recognition.

The fabrication of optically active inorganic nanomaterials with chiral superstructures attracts attention because of their potential applications in chemical sensing and non-linear optics. Here, we present a facile way to prepare TiO2 nanofibres, in which the nanocrystals are helically arranged into a chiral superstructure. Notably, the chiral superstructure shows strong optical activity due to the difference of absorbing left- and right-handed circularly polarized light. This special optical activity resulted from electron transition from the valence band to the conduction band of TiO2 through a vicinal effect of helically arranged TiO2 nanocrystals.

To investigate the expression of Wnt3a, Wnt10b, β-catenin and DKK1 in the periodontal ligament (PDL) during orthodontic tooth movement (OTM) in rats.Nickel-titanium closed-coil springs were used to deliver an initial 50 g mesial force to the left maxillary first molars in 30 rats. The force was kept constant for 1, 3, 5, 7, 10 and 14 days until the animals were sacrificed. The right maxillary molars without force application served as control. Paraffin-embedded sections of the upper jaws were prepared for histological and immunohistochemical analyses to detect Wnt3a, Wnt10b, β-catenin and DKK1 expression in PDL.Wnt3a, Wnt10b, β-catenin and DKK1 were expressed on both the ipsilateral and contralateral sides of PDL in each group. After the application of orthodontic force, the expression of β-catenin and DKK1 was initially increased and then decreased on both sides, with maximal levels of expression at day 7 and day 10, respectively. On the compression side, Wnt3a and Wnt10b levels started to increase at day 5, while on the tension side, these two molecules began to increase at day 1. Furthermore, the expression levels of Wnt3a, Wnt10b, and β-catenin were much stronger on the tension side than on the compression side at any of the observation points, while DKK1 level was much higher on the compression side.Wnt3a, Wnt10b, β-catenin and DKK1 expression may be related to the periodontal tissue remodeling following the application of an orthodontic force in rats. These observations suggest that the Wnt/β-catenin signaling pathway may play a crucial role in periodontal tissue remodeling during OTM.

In order to further study the effectiveness and applicability of the glowworm swarm optimization algorithm, this paper proposed a discrete glowworm swarm optimization algorithm with an adaptive neighborhood search, and used it to solve traveling salesman problem (TSP). Based on the analysis and optimization of the different genetic operations, a new adaptive DGSO algorithm is presented (ADGSO), which is effective for both local search and global search. And we defined a new kind of glowworm, which can adjust the flight length of particles by self-adapting. By solving the different instances of TSP, experimental results indicate that ADGSO has a remarkable quality of the global convergence reliability and convergence velocity. It solved the problems of traditional DGSO algorithm “premature”. Unlike existing TSP approaches that often aggregate multiple criteria and constraints into a compromise function, the proposed ADGSO optimizes all routing constraints and objectives simultaneously, which improves the routing solutions in many aspects, such as lower routing cost, wider scattering area and better convergence trace. The ADGSO is applied to solve the TSP, which yields solutions better than or competitive as compared to the best solutions published in literature.

Traffic network distribution based on distribution center problem (TNDBDCP) is put forward, which can not be solved by traditional algorithms. In order to solve TNDBDCP, Particle Swarm Optimization (PSO) is put forward based on the idea of global and feasible searching. In the PSO, introducing check function ensures the feasibility of particle swarm, which is designed based on the neighborhood search method which only uses one loop program to meet the requirement of time constraint and radialized network structure; more reasonable fitness function is designed based on the relationship between spanning tree and its cotree; improvements for updating the position of particle make the current position of particle be beneficial to being close to the best position of particle in its neighborhood.

The main core problem in optimization filed is to apply the optimization method devised by adopting a meta-heuristic algorithm to large-scale traffic network layout problem based on contribution center (TNLOSP). Improved Genetic Algorithm (IGA) is proposed to deal with this problem instead of traditional one. Two improvements are added to previous algorithm: Prim Stochastic Algorithm (PSA) and a fair competition strategy. In tuning phase, such core parameters in crossover rate, fairness coefficient \(p_{0}\), and the like as are synchronously optimized; In comparative analysis phrase, in large part as a consequence of comparison, the thesis focuses on a great deal of experimental analysis on determining more accurately some advantages of the algorithm. Showing though the experiment that improved algorithm has more advantages in efficiency and precision of solutions than traditional one by testing different scale populations. Therefore, proving that these improvements are of feasibility.

Chiral semiconductor nanomaterials with optical activity have intrigued magnificent attention due to their potential technological applications, but so far there have been no reports of chiral optically active CuO nanofilms. In this work, a facile chemical method to deposit chiral CuO nanoflowers on an activated quartz substrate is demonstrated. Three levels of chirality in CuO nanofilms are demostrated by structural analysis: tertiary helically arranged “nanopetals” assembled from secondary helically stacking “nanoplates.” Primary twisting chiral nanostructure of the nanoplate is believed to exist after careful examination on circular dichroism optical responses given by the CuO nanofilms. Originated from hierarchical chiralites, the CuO films exhibit both the electron transition absorption-based optical activity at the characteristic absorption bands and reflection-based optical activity arising from the long-range periodic structure at the circular Bragg resonance.

Road networks are the main carriers of social-economic activities as well as cargo transportation. Given the importance of city road networks, understanding their robustness is becoming an important issue for urban planning and traffic management at all levels. Analyzing the robustness of city road networks quantitatively has always been a difficult task due to the complexity of city road networks and the distinct difference between network structures at multiple granularities. In this paper, we adopt some quantitative methods rooted from complex network science to explore the robustness of city road networks at three different granularities. The results show that the road segment based method lacks the sensitivity under intentional attack, and the stroke based method cannot represent the split procedure of city road networks under attack. Neither of them is appropriate to evaluate the robustness of city road networks. The community based evaluation method, which can reflect the network change situation under attack at a mesoscopic view, is arguably a suitable method for robustness evaluation of city road networks.

Helical symmetry can be found in most flowers with a rotation of contort petal aestivation. For micro- and nanoscale analogies, flower mimicking structures have been reproduced; however, the conceptual chirality of “nanoflowers” has not yet been defined. Here, the chirality of the “flower” was defined by its nanosized chiral structure and consequent optical activity (OA), opening new horizons for the physical theory and chiral materials. We report the surfactant-mediated hydrothermal synthesis of chiral CuO nanoflowers using sodium dodecyl sulfate (SDS) as a structure-directing agent, an amino alcohol as a symmetry-breaking agent, and cupric salt as the inorganic source. Two levels of hierarchical chirality exist for a CuO nanoflower including primary helically arranged “nanoflakes” and secondary helical “subnanopetals” that form “nanopetals”. The nanoflowers exhibited a prominent optical response to circularly polarized light (CPL) at the absorption bands characteristic of CuO.

Chiral metal oxide complexes with tunable optical response to circularly polarised light over the full range of the UV-Vis absorption band were synthesised. This optical activity was attributed to electronic transitions from the ground state to the excited state or from the valence band to the conduction band under an asymmetric electric field.

Many complex networks demonstrate a phenomenon of striking degree correlations, i.e., a node tends to link to other nodes with similar (or dissimilar) degrees. From the perspective of degree correlations, this paper attempts to characterize topological structures of urban street networks. We adopted six urban street networks (three European and three North American), and converted them into network topologies in which nodes and edges respectively represent individual streets and street intersections, and compared the network topologies to three reference network topologies (biological, technological, and social). The urban street network topologies (with the exception of Manhattan) showed a consistent pattern that distinctly differs from the three reference networks. The topologies of urban street networks lack striking degree correlations in general. Through reshuffling the network topologies towards for example maximum or minimum degree correlations while retaining the initial degree distributions, we found that all the surrogate topologies of the urban street networks, as well as the reference ones, tended to deviate from small world properties. This implies that the initial degree correlations do not have any positive or negative effect on the networks' performance or functions. Keywords: Scale free, small world, rewiring, rich club effect, reshuffle, and complex networks, Comment: 15 pages, 8 figures, and 3 tables

The soybean gene Glyma10g34760 appears to encode a RAV2-like transcription factor orthologue (DQ147914; hereafter GmRAV) based on sequence similarity. The gene is a member of the ERF/AP2 transcription factor family that has been shown to be increased in transcript abundance by cytokinins (CKs). Transgenic GmRAV-overexpressing (-ox) tobacco plants exhibited increased CK signalling-related phenotypes including dwarfism, reduced apical dominance, extreme longevity, vigorous outgrowth of lateral buds, small and dark green leaves, reduced root growth, repressed flowering under both long- and short-day conditions, and altered sensitivity to daylength. In contrast, inhibition (-i) of GmRAV in soybean displayed the opposite phenotypic alterations which were consistent with defects in CK signalling. Phenotypes included earlier time of emergence; reduced numbers of branches, leaves, and flower buds; increased plant height; increased apical dominance; and earlier flowering and maturity. GmRAV-i soybean was less sensitive to cytokinin in hypocotyls and root growth inhibition assays. GmRAV-i soybean showed decreased frequency of adventious shoot formation in tissue culture in the presence of CKs, which might be attributed to the significantly decreased activities of CUC2, STM, and WUS involved in shoot meristem specification. GmRAV protein was localized in the nucleus in leaves. The GmRAV promoter-β-glucuronidase (GUS) fusion was largely expressed in a meristematic region of the shoot apex, which was consistent with expressed sequence tag and microarray data. GmRAV was inferred to play a key role in CK and photoperiod signalling that subsequently regulated plant development.

In order to provide quicker, and more comprehensive network service for users, and to bring more convenience for the development of the SP/CP(Service Provider/Content Provider), we propose an open service system whose architecture and the standardization of the open API(Application Programming Interface) are discussed more in this paper. To design such a system, Firstly, the common services model, which could realize the auto choice of the most appreciate services among the services provided by different SP/CP, needs to be built through extracting the service characteristic from different network services. Secondly, it must be ensured that, through the standardized open API, all the common services in different fields could access the service integration and publishing platform. The advantage is that the users can not only realize the mashup of services they need, but also are able to release the services they have developed on such a platform.

In this paper, we aim to mine turn delay at different times and turn types in city road network based on personal GPS collected trajectories. We provide a method to effectively solve the problem for computing turn delay. By using this method, we can rapidly process massive trajectory data, to explore and predict turn delay in city road network. Through map-matching and pre-processing work for trajectory data, we firstly extract turn delay records from the time that people pass across a road intersection. Limited by the range of trajectory collection, these turn delay records cannot cover all road intersection and all different times. Therefore, we secondly propose a prediction model based on Neural Networks to handle these records. In this prediction model we have considered both geography neighborhood effect and topological relationship of road intersections. Finally, we tested the efficiency of this method through cross-validation by using 8986 trajectories derived from 165 pedestrians in a time period of three years. It demonstrates that the proposed method can obtain a higher accuracy of turn delay prediction than traditional methods which usually ignore topological characteristics of road intersections.

Implementing convenient traveling information service is a crucial task for deploying intelligent transportation system applications and location-based services. Traditional traveling information service systems, such as car navigation systems or web maps, only provide relatively static information which doesn't truly reflect the dynamic changes of traffic situation, and result in very limited practical use. Although there have emerged some car navigation products and other applications involving dynamic traffic information, considering the rapid change of city traffic situation, these applications still face practical difficulties for all the information received real-timely will get outdated within a few minutes, which makes the so called dynamic applications basically time-slice limited static ones. Aiming at such a problem, a short-term traffic prediction approach and a consequent real-time route guidance process are presented in this paper which integrates historical traffic based statistical reasoning, real-time traffic and events processing, with a BP neural network based analytical model, to forecast the situation and evaluate the influence of traffic during the traveling process. Then a collaboration working framework is set forward to implement dynamic route guidance, with the combination of a GIS server, a traffic forecasting server and a database management system. The traffic forecasting server, integrating with historical statistics reckoning continuously receives real-time traffic information obtained from floating vehicles, traffic events described in natural language, and achieves short-term forecasting results for the whole road networks, then fed the results back into the database management system and GIS server, so that a time-dependant optimal routing can be conducted through a dynamic least traveling time algorithm developed in this study. A prototype navigation system fulfilling the above aspects has been developed and the dynamic route choice approach demonstrated on road networks in the downtown area of Beijing city. The approach presented in this paper is argued to provide a practical solution for real-time public traveling information service and dynamic web maps.

Nano-coned array of Cu were prepared by electroless plating with special crystallization conditioning agent. The morphologies of nano-coned array were observed by FE-SEM. The influences of active time in PdCl 2 , concentration of NiSO 4 ·6H 2 O, crystallization conditioning agent, pH and temperature of plating solution were discussed. Then, the possible reasons of the influence on the growth of nano-coned array were investigated. NiSO 4 ·6H 2 O was proved as catalytic active agent. The optimum preparation conditions were fixed. The crystal crystallographic orientation and elements of the nano-coned array were measured using TEM and EDX. The nano-cones consist of 95.57% copper and 4.43% nickel. The crystal crystallographic orientation of them is typical copper FCC single crystal.

The optical chirality induced at the absorption bands due to electronic exciton coupling of the transition dipole moments between chromophores in close proximity is ubiquitous in helical organic materials. However, inorganic materials with optical activity resulting from electronic transitions have not been explored. Here we report the synthesis of chiral TiO2 fibres via transcription of the helical structure of amino acid-derived amphiphile fibres through coordination bonding interactions between the organics and the TiO2 source. Upon calcination, the as-prepared amorphous TiO2 double-helical fibres with a pitch length of ~100 nm were converted to double-helical crystalline fibres with stacks of anatase nanocrystals in an epitaxial helical relationship. Both the amorphous and anatase crystalline helical TiO2 fibres exhibited optical response to circularly polarized light at the absorption edge around ~350 nm. This was attributed to the semiconductor TiO2-based electronic transitions from the valence band to the conduction band under an asymmetric electric field., Optical activity resulting from electronic transitions in chiral inorganic materials is rare. Liu et al. report the synthesis of amino acid-derived amphiphile templated chiral TiO2 fibres, which exhibit an optical response to polarized light resulting from valence to conduction band electronic transitions.

Urban road traffic is spatially autocorrelated.The change of traffic on certain road will quickly affect the traffic on nearby roads,which will alter the overall traffic status within a neighborhood.Revealing the spatial autocorrelation structure in urban road traffic is important for traffic planning,traffic controlling and traffic guidance.The traffic interaction between neighboring roads is not isotropy.The traffic change on certain road does not equally spread to each spatially adjacent road,but concentrate on some of them.Thus only using spatial adjacency to define adjacent roads cannot well reveal the spatial autocorrelation in urban road traffic.Recent research has proved that the dynamic flow on networks highly depend on the structure of networks.Characterizing the structure of urban road network is essential to reveal the spatial autocorrelation in urban road traffic.The aim of this research is to reveal the spatial autocorrelation of urban road traffic based on road network characterization.We first investigate the modular character and hierarchal feature of urban road network quantitatively.The modulars in road network are defined as a group of closely connected neighboring road segments and identified by community detection algorithm from complex network theory.The hierarchal feature of urban road network helps to determine the structural importance of road segments.Topological roles are defined based on the structural importance of road segment.Then we provide a novel approach to define adjacent road segments based on the topological roles in spatially adjacent road segments.Two road segments defined as adjacent road segments not only locate in a nearby neighborhood but also have the same topological roles.A set of adjacent roads constitute a spatial related set.Experiment results on the road network of Beijing imply that the spatial related sets identified by the proposed approach can capture the spatial autocorrelation structure of urban road traffic.