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In this study, a ternary nanostructured α-Fe2O3/Au/TiO2 film with integrating a crystalline α-Fe2O3 core, metallic Au nanoparticles (NPs), and an amorphous TiO2 overlayer is fabricated and examined as a photoanode for photoelectrocatalytic water splitting. Under simulated solar illumination, the as-prepared photoanode exhibits a four-fold increase (1.05 mA cm−2) in photocurrent density at 1.23 V versus reversible hydrogen electrode (RHE) relative to bare α-Fe2O3. Based on systematic investigations, it is proposed that Au NPs extract photoholes from the bulk of α-Fe2O3 core and then shuttle them to the outer TiO2 overlayer, and meanwhile, TiO2 overlayer efficiently captures and stores the photoholes and facilitates the hole injection into electrolyte. Thus, the remarkably improved photoelectrocatalytic water splitting performance of α-Fe2O3/Au/TiO2 photoanode is attributed to the significantly suppressed bulk and surface charge recombination due to the relayed pumping of the photogenerated charge carriers through the photoanode/electrolyte interfaces reconstructed by Au NPs and TiO2 overlayer.

A flower pollination algorithm is proposed based on the hormone modulation mechanism (HMM-FPA) to solve the no-wait flow shop scheduling problem (NWFSP). This algorithm minimizes the maximum accomplished time. Random keys are encoded based on an ascending sequence of components to make the flower pollination algorithm (FPA) suitable for the no-wait flow shop scheduling problem. The hormone modulation factor is introduced to strengthen information sharing among the flowers and improve FPA cross-pollination to enhance the algorithm global search performance. A variable neighborhood search strategy based on dynamic self-adaptive variable work piece blocks is constructed to improve the local search quality. Three common benchmark instances are applied to test the proposed algorithm. The result verifies that this algorithm is effective.

The photoelectrochemical (PEC) water splitting activity of Nb and Ta-doped hematite (α-Fe

Solar hydrogen conversion via photoelectrochemical water splitting is an important technology for energy and environment sustainability. Since the pioneering work of Fujishima and Honda in 1972, tremendous research on semiconductor-based photoelectrochemical water splitting has yielded better understanding of the processes as well as encouraging development of high efficiency photoelectrodes for solar hydrogen generation. Given the narrow band gap enabling excellent optical absorption, increased charge carrier density and accelerated surface oxidation reaction kinetics become the key points for improved photoelectrochemical performances for water splitting over α-Fe2O3 photoanodes. In this talk, some recent progresses in surface modified α-Fe2O3 for photoelectrochemical solar water splitting in our group will be introduced. By engineering the surface structures of α-Fe2O3 nanorods with AgxFe2-xO3, TiO2 and HfO2 overlayers, the surface charge recombination was greatly inhibited and the surface water oxidation kinetics were efficiently accelerated, resulting in remarkable enhancement in PEC water splitting performances.

Hematite (α-Fe2O3) has been extensively suggested as a superior photoanode for the photoelectrochemical (PEC) water splitting, owing to its natural abundance, high chemical stability, and theoretical solar-to-hydrogen (STH) efficiency (16.8%). Nevertheless, the recalcitrant electron−hole recombination resulting in poor charge separation and injection efficiency limits its PEC performance. Herein, a simple hydrothermal/atomic layer deposition (ALD) process was used to fabricate two types of HfO2 functionalized hematite (i.e., HfO2 overlayer and nanoparticles modified α-Fe2O3, HfFe-L and HfFe-P for short) photoanodes. It was revealed that HfO2 overlayer and nanoparticles could successfully passiviate the surface trap states of hematite, resulted in enhanced PEC performances for both HfFe-L and HfFe-P. More surprisingly, the photocurrent density of the HfFe-P reached as high as 1.21 mA cm-2 at 1.23 vs. RHE, with ~4.8 and ~3.3 fold enhancement as compared to that of the bare hematite and even HfFe-L, respectively. Such great PEC performance enhancement in HfFe-P was revealed to be attributed to the multifunction of HfO2 nanoparticles distributed on the surface of hematite nanorod arrays, which not only passivated surface defects to suppress the surface charge recombination by eliminating the surface trapping states, but can also facilitated the hole extraction from bulk of hematite to hematite/electrolyte interface.

The deep volcanic reservoir in Zhungeer Basin is buried in over 4000m depth, which is characterized by complex lithology (breccia, andesite, basalt, etc.), high elastic modulus and massive natural fractures. During hydraulic fracturing, hydraulic fracture will propagate and natural fractures will be triggered by the increasing net pressure. However, the extension of fractures, especially natural fractures, would aggravate the leak-off effect of fracturing fluid, and consequently decrease the fracturing success rate. 4 out of 12 fracturing wells in the field have failed to add enough proppants due to fluid loss. In order to increase the success rate and efficiency of hydraulic fracturing for deep volcanic reservoir, based on theoretical and experimental method, the mechanism of fracturing fluid leak-off is deeply studied. We propose a dualistic proppant scheme and employ the fluid loss reducer to control the fluid leak-off in macro-fractures and micro-fractures respectively. The proposed technique remarkably improved the success rate in deep volcanic rock fracturing. It bears important theoretical value and practical significance to improve the hydraulic fracturing design for deep volcanic reservoir.

Chicken swarm optimization is a new intelligent bionic algorithm, simulating the chicken swarm searching for food in nature. Basic algorithm is likely to fall into a local optimum and has a slow convergence rate. Aiming at these deficiencies, an improved chicken swarm optimization algorithm based on elite opposition-based learning is proposed. In cock swarm, random search based on adaptive t distribution is adopted to replace that based on Gaussian distribution so as to balance the global exploitation ability and local development ability of the algorithm. In hen swarm, elite opposition-based learning is introduced to promote the population diversity. Dimension-by-dimension greedy search mode is used to do local search for individual of optimal chicken swarm in order to improve optimization precision. According to the test results of 18 standard test functions and 2 engineering structure optimization problems, this algorithm has better effect on optimization precision and speed compared with basic chicken algorithm and other intelligent optimization algorithms.

Deep volcanic reservoir in Xinjiang Zhungeer basin is buried over 4000m, the elastic modulus of reservoir rocks is high, hence it is difficult to initiate hydraulic fracture during fracturing operation; fracturing fluid filtration is serious and hard to be controlled due to the massive natural fractures in reservoir. Because of the serious heterogeneity along both horizontal and vertical direction, the optimum targets of design fracturing for different well layers are not the same. 4 out of 12 fracturing wells have not achieved the target amount of proppant. Ultimately, fracturing success rate is low and the production increase after fracturing shows a big difference among different wells. In order to improve the success rate and efficiency of deep volcanic reservoir fracturing, based on the analysis of the difficulties in previous fracturing operation, combined with the geological characteristics of reservoir, we optimized the key engineering parameters of deep volcanic rock fracturing, including perforation parameters, filtration parameters, fracture parameters and operation parameters. Results of fracturing design optimization bear an important guiding significance for improving the fracturing success rate and efficiency of deep volcanic reservoir in Zhungeer basin, Xinjiang province.

Anisotropic nanopatterns have potentials in constructing novel plasmonic structures which have various applications in such as super-resolution microscopy, medicine, and sensors. However, it remains challenging to build big anisotropic nanopatterns that are suitable for big noble metal nanoparticles. Herein, we report a simple and reliable strategy for constructing DNA origami-based big anisotropic nanopatterns with controlled size and shape, nanoscale resolution, and fully addressability. Two kinds of basic DNA origami nanoblocks - cross-shaped and rectangular DNA origami units were used. We have demonstrated that by encoding nanoblocks' edges, anisotropic higher-order nanopatterns, such as dimer, trimer, tetramer and mini "windmill" like pentamer nanopatterns could be constructed. To show the potential use as template to direct the assembly of anisotropic nanoparticles arrays, a proof of concept work was conducted by anchoring streptavidin nanoparticles on the "windmill" template to form a chiral array. Significantly, these nanopatterns have the sizes of hundreds of nanometers, which are in principle also suitable for big noble metal nanoparticles arrays.

This paper proposes a complete parametric approach for eigenstructure assignment in second-order system Mq+Dq+kq=cu using the displacement-plus-acceleration feedback controller. The expressions of closed-loop eigenvector matrix and feedback gains are in direct closed forms in terms of the closed-loop eigenvalues and a group parameter vectors, which represents the degree of design freedom. The main advantage of the proposed method is solved directly in matrix second-order framework, without transformation into the first-order form, and the numerical stability is better because it used only right coprime factorization and simple matrix transformation. The proposed algorithm is simple and does not contain ‘go back’ procedures. Finally, computational results show its effect and simplicity.

Ta-doped hematite (α-Fe2O3) nanorod array films were successfully prepared on fluorine-doped tin dioxide (FTO) coated glass substrates via a facile solution growth process with TaCl5 as a Ta doping precursor. Under 1 sun illumination and at an applied potential of 1.0 V vs. Ag/AgCl, the Ta-doped α-Fe2O3 photoanode with optimized dopant concentration showed a photocurrent density as high as 0.53 mA cm(-2), which was about 3.5 times higher than that of the undoped sample. As demonstrated by Mott-Schottky and X-ray absorption spectroscopy measurements, considerable increase in photoelectrochemical (PEC) performance achieved for Ta-doped α-Fe2O3 nanorod films should be mainly attributed to the increased electron donor density induced by Ta doping. However, with superfluous Ta doping, the [110]-oriented nanorod structure was destroyed, which caused greatly restrained photoinduced holes transferring to the surface and retarded surface water oxidation reaction, leading to decreased PEC water splitting activity. This study clearly demonstrated that doping could be effective to enhance the PEC activity of α-Fe2O3 nanorods as photoanodes, while it is of great necessity to balance the trade-off between the electronic structure and nanostructure evolution by optimizing the dopant concentration, for increased donor density and meanwhile with the nanorod nanostructure well preserved for directed charge transfer.

Apart from providing the material for genetic information storage, DNA has also been regarded as a useful building block in the field of nanotechnology, which is known as DNA nanotechnology. Based on the Watson-Crick base-pairing and the famous double helical structure, a library of DNA 2D or 3D nanostructures has been designed, constructed and characterized, by either tile-based or origami-based self-assembly. More significantly, other molecules/nanomaterials can be organized on those DNA ensembles to achieve highly ordered arrays or specific patterns in nanometer spatial resolution. In this review, we summarize recent progress in creating DNA nanoarchitectures, and discuss potential applications in DNA-based nanofabrication.

A solution-phase DNA chip is produced using DNA origami-based asymmetric self-assembled tiles incorporating single-stranded DNA linear probes. This DNA origami chip is fully spatially addressable, without having to use position index oligonucleotides. The DNA hybridization is readily detected via atomic force microscopy.

The photoelectrochemical (PEC) water splitting activity of Nb and Ta-doped hematite (α-Fe2O3) nanorods was investigated with reference to electronic structures by in situ synchrotron x-ray absorption spectroscopy (XAS). Current density-potential measurements demonstrate that the PEC activity of α-Fe2O3 nanorods depends strongly on the species and concentrations of dopants. The doping of α-Fe2O3 nanorods with a low level of Nb or Ta can improve their electrical conductivity and thereby facilitate charge transport and reduced electron-hole recombination therein. The photoconversion effects of Nb and Ta-doped α-Fe2O3 by in situ XAS in the dark and under illumination revealed opposite evolutions of the spectral intensities of the Fe L-edge and Nb/Ta L-edge, indicating that charge transfer and a conduction pathway are involved in the photoconversion. Analytic in situ XAS results reveal that the α-Fe2O3 that is doped with a low level of Nb has a greater photoconversion efficiency than that doped with Ta because Nb sites are more active than Ta sites in α-Fe2O3. The correlation between PEC activity and the electronic structure of Nb/Ta-doped α-Fe2O3 is examined in detail using in situ XAS and helps to elucidate the mechanism of PEC water splitting in terms of the electronic structure.

To the problem of the traditional parameters optimization algorithm may level into local optimal, a parameter optimization method crossover mutation artificial bee colony based on artificial bee colony algorithm is proposed to solve this problem and applied toi¾źintrusion detection. And introduced an improved artificial colony algorithm based on crossover mutation operator, the whole bee colony could be divided into two sub-populations according to the fitness value of colony and effectively avoid local optimum and enhance convergence speed,i¾źuse standard test functions to verify the effectiveness of the algorithm. And the proposed algorithm's performance is tested by the KDD-99 datasets, the experimental results show that this method can effective improve the classification performance of intrusion detection.

Molecular computing holds great promise for diagnosis and treatment of diseases at the molecular level; nevertheless, designing molecular logic gates to operate programmably and autonomously for molecular diagnostics still remains challenging. We designed logic gates on DNA Origami for microRNA analysis. As a demonstration, two indicators of heart failure, microRNA-21 and microRNA-195, were selected as the logic inputs. The logic gates contain two main modules: computation module and output module, performing in a single DNA Origami nanostructure. The computation module recognizes disease indicators, while the output module display different nanoscale symbols, “+” (positive) or “–” (negative), depending on the computing results. We demonstrated that the molecular logic gates worked well with single and two input combinations.

Self-assembled DNA origami nanostructures have shown great promise for bottom-up construction of complex objects with nanoscale addressability. Here we show that DNA origami-based ID nanoribbons and nanotubes are one-pot assembled with controllable sizes and nanoscale addressability with high speed (within only 10-20 min), exhibiting extraordinarily high cooperativity that is often observed in assembly of natural molecular machines in cells (e.g. ribosome). By exploiting the high specificity of DNA-based self-assembly, we can precisely anchor proteins on these DNA origami nanostructures with sub-10 nm resolution and at the single-molecule level. We attach a pair of enzymes (horseradish peroxidase and glucose oxidase) at the inner side of DNA nanotubes and observe high coupling efficiency of enzyme cascade within this confined nanospace. Hence, DNA nanostructures with such unprecedented properties shed new light on the design of nanoscale bioreactors and nanomedicine and provide an artificial system for studying enzyme activities and cascade in highly organized and crowded cell-mimicking environments.

Individual biomolecular binding events were recorded in situ by combining time-lapse atomic force microscopy and DNA origami. Single streptavidin molecules bound to specifically biotinyated DNA origami were simply counted as a function of time to obtain a direct measure of the binding rate.

To solve chaotic time series prediction problem, a novel Prediction approach for chaotic time series based on Immune Optimization Theory (PIOT) is proposed. In PIOT, the concepts and formal definitions of antigen, antibody and affinity being used for time series prediction are given, and the mathematical models of immune optimization operators being used for establishing time series prediction model are exhibited. Chaotic time series is analyzed and corresponding sample space is reconstructed by phase space reconstruction method; then, the prediction model of chaotic time series is constructed by immune optimization theory; finally, using this prediction model to forecast chaotic time series. To demonstrate the effectiveness of PIOT, the three typical chaotic nonlinear time series are generated by nonlinear dynamics systems that are Lorenz, Mackey-Glass and Henon, respectively, and are used for simulating prediction. The simulation results show that PIOT is a feasible and effective prediction method, and meanwhile provides a novel prediction approach for chaotic time series.

As traditional negative selection algorithms need to calculate the distances between initial detectors and all the self data, the efficiencies of them are too low. In this article, before the creation process of detectors, the self data is pretreated to be a SS-Tree, and then the negative selection process is transformed into the data query process in the self SS-Tree to improve the efficiency of detectors creation.

Attack and defense is the two important aspects of network security issue. Network security situational assessment has focused on attack roundly. Numbers of network security situational assessment models have been put forward based on attack and threat. Those methods have obtained good results. On the other hand, defense lacks careful consideration. Defense embodies system tolerance. System tolerance contains three important factors: system tolerance to attack, system asset tolerance, and system survivability. The article will introduce a network security situational assessment model based on attack and defense. Consult the existent models of network security situational assessment to summarize a hierarchical model. The hierarchical model based on attack mainly. Then we will use the three factors of system tolerance to mend the model. The new hierarchical model based on attack and defense will be closer to realistic security situation status. The corresponding experiment proves that the improved model considered attack and defense has better effect.

Forecast of network security situation is an important part of network security situational assessment. The concept of network security situational assessment will be introduced. Then a model of network security situational assessment is summarized based on the concept. On the other hand, The method of GM(1,1) modified by residual error is mentioned. And this method will be improved into optimal fuzzy grey model. The model of optimal fuzzy grey will be used to forecast value of network security situational assessment. The results show better effects in simulation test, compared to the original model.

Highly efficient semiconductor photoelectrodes for solar hydrogen production through photocatalytic water splitting are a promising and challenge solution to solve the energy problems. In this work, Ag/Cu2O/ZnO tandem triple-junction photoelectrode was designed and prepared. An increase of 11 times of photocurrent is achieved in the Ag/Cu2O/ZnO photoelectrode comparing to that of the Cu2O film. The high performance of the Ag/Cu2O/ZnO film is due to the optimized design of the tandem triple-junction structure, where the localized surface Plasmon resonance of Ag and the hetero-junctions efficiently absorb solar energy, produce, and separate electron-hole pairs in the photocathode.

Guaranteed cost control for a class of linear discrete-time switched systems with parameter uncertainty is studied. The purpose is to design a state feedback control law such that the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound for all admissible uncertainties. Two different sufficient conditions on the existence of guaranteed cost controllers are derived based on a switched Lyapunov function (SLF) method together with linear matrix inequality (LMI) approach. Furthermore, a convex optimization problem with LMIs constraints is formulated to design a suboptimal guaranteed cost controller. A numerical example demonstrates the effect of the proposed design approach.

This paper investigates robust L2 - Linfin filtering problem for a class of linear uncertain time-delay systems. The uncertainties in the system are time-varying and bounded, and time delays are time-varying. The objective is to design linear memoryless filters such that for all uncertainties, the resulting augmented system is robust stable independent of delays and satisfies the proposed L2 - Linfin performance. Based on Lyapunov stability theory in time-delay systems, a sufficient condition on the existence of robust L2 - Linfin filters is derived. The problem of robust L2 - Linfin filters is turned into the solution problem of linear matrix inequalities. A numerical example is given to demonstrate the effect of the proposed approach

This paper is concerned with the problems of robust sliding mode filter designs for a class of nonlinear systems with parameter uncertainties and time-vary delays. The nonlinearities are assumed to satisfy global Lipschitz conditions and parameter uncertainties reside in a polytope. The resulting filter is of the Luenberger type with discontinuous form, it guarantees the robust asymptotic stability of the filtering error dynamics for all admissible uncertainties. A sufficient condition with delay-dependent is given for the existence of such a filter in terms of linear matrix inequalities (LMIs). The resulting filter can be easily obtained from the optimal solutions of this set of LMIs.

In this paper, the problem of stochastically reliable H/sub /spl infin// control for a class of uncertain stochastic systems with time-varying delays and actuator failures is considered. The time-varying delay is assumed to be bounded but unknown. A sufficient condition on stochastic reliable stabilizability is established based on the stability theory for stochastic differential equations. For all admissible uncertainties and actuator failures occurred within the prespecified subset, stochastically reliable H/sub /spl infin// controllers are designed t in terms of linear matrix equalities such that the closed-loop system with actuator failures is stochastically stable independent of delay and satisfies performance constraint of disturbance attenuation level represented by an H/sub /spl infin// norm bound constrain.

ZnFe2O4 modified α-Fe2O3 nanorod array films were successfully synthesized by aqueous solution growth followed by a spin coating process and studied for photoelectrochemical (PEC) water splitting under solar light. Through the spin coating process, ZnFe2O4 was found mainly to exist at the top surface of the α-Fe2O3 nanorod arrays. After being modified by ZnFe2O4, the α-Fe2O3 nanorod film was identified as a suitable surface treatment, and showed an increased photocurrent density when used as the photoanode. It was demonstrated that ZnFe2O4 increased the charge carrier density and acted as the oxidation cocatalyst. These results suggested that surface treatment by ZnFe2O4 should be a practical strategy to improve the efficiency of α-Fe2O3 or other metal oxide photoanodes for PEC solar fuel conversion.

The article by Wang, Lin and Chou illustrates the integration and control of a 500W self-humidified proton exchange membrane fuel cell (PEMC) system. By applying some classic modern control theory as tools, some robust controllers are designed to regulate the air and hydrogen flow rates. In this article, the authors give detailed design procedure from the mathematical modeling to the controller design. Somemodern control theories, such as systems identification, Hinf control and optimal control are synthetically used. In the Hinf control based design, a key problem is the selection of the weighting function. In this article, such a procedure is shown in details. Due to these reason, in our opinion thework of this article can be viewed as a successful practical application of advanced control theory. It may help to reduce the gap between control theory and control engineering. The overall design procedure of the considered 500W self-humidified PEMC system includes the following aspects.