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In this work, to investigate the physical vapor deposition (PVD)-deposited TiN coating on the TiN(001) substrate, the process was simulated using the molecular dynamics (MD) method with the 2NN-MEAM (nearest-neighbor modified embedded atom method) potential. The results revealed that the growth mode of TiN film is determined by incident energy. When the incident energy is low, the deposited atoms have weak mobility after momentum transfer with the substrate and cannot fill the vacancy in the TiN film, and thus the TiN film eventually grows in an island shape. When increasing the incident energy, the vibration of atoms on the deposited surface is intensified, and some atoms on the film surface jump. Therefore, the non-thermal diffusion occurs, resulting in defect reduction on the TiN film and forming a lamellar growth with a more continuous and complete film. The growing incident energy continuously reduces the surface roughness of the TiN film.

To obtain excellent properties in 7××× series aluminum alloys, the heat treatment process used is an important factor. This needs to be chosen according to the different alloy compositions. A 7××× series aluminum alloy with high zinc content (Zn/Mg > 4, Mg/Cu = 1) was prepared. Studying the heat treatment process of the alloy is important to guide companies in its industrial production. The optimum heat treatment process is explored from a microstructure point of view. The alloy was melted and cast in the laboratory using a metallurgical method. The microstructure, fracture morphology, and mechanical properties of the alloy were examined by metallographic microscopy, scanning electron microscopy, transmission electron microscopy (TEM), and tensile testing. Research on the alloy solution treatment was emphasized. The results showed that the solution effect was optimum at 470 °C × 1 h during a single-stage solution treatment. The recrystallization degree was low when the two-stage solution treatment process was 450 °C × 0.5 h + 475 °C × 0.5 h due to the release of deformation energy at low temperature; at the same time, the second-order solid-solution temperature was high, the solid-solution effect was better than in the single-stage solid-solution treatment, and the comprehensive mechanical properties of the alloy were better.

Aiming at the problems of many types of grid operation indicators, complex secondary indicators, and difficulty in qualitative or quantitative analysis, this paper proposes a grid operation indicator screening method based on mutual information with maximum correlation and minimum redundancy coefficient. First, sort out the relevant indicators of power grid operation evaluation at home and abroad, and then qualitatively screen the secondary indicators under the indicator category from the aspects of system operating efficiency, reliability, and economy. Secondly, based on the mutual information theory, the group correlation entropy values of different secondary indicators are obtained, and the maximum correlation-minimum redundancy coefficient is used to screen the entropy values of related index categories with the optimal correlation degree. These entropy values can maximize the mining of different The relevance of the secondary indicators under the category can minimize the redundant information between. Finally, it is verified by scoring a typical regional power grid operation. The results show that the proposed index correlation screening method can simply and effectively evaluate the operation level of the smart grid.

Smart grid operation data presents the characteristics of large amount of data, multiple types of data and rapid growth rate, which is not conducive to quantitative analysis of actual operation level of power grid. In order to quickly and effectively screen the smart grid operation indicators, simplify the operation index system and reduce the index redundancy, this paper proposes a quantitative analysis index to measure the effectiveness and redundancy of operation indicators based on the maximum relevance minimum redundancy criterion. Then, through quantitative analysis of indicators, the optimization model is constructed. Finally, the screening process is transformed into a 0–1 programming problem by coding, and the optimal index set is obtained by exhaustive method. The results show that the proposed screening method improves the information content of the index system and reduces the index redundancy, which verifies the rationality and effectiveness of the screening method.

In order to remove the Gaussian noise in the image more effectively, a convolutional auto-encoder image denoising model combined with the perception module is proposed. The model takes the whole image as input and output, uses the concept module to denoise the input noise image, uses the improved concept deconvolution module to restore the denoised image, and improves the denoising ability of the model. At the same time, the batch normalization (BN) layer and the random deactivation layer (Dropout) are introduced into the model to effectively solve the model over fitting problem, and the ReLu function is introduced to avoid the model gradient disappearing and accelerate the network training. The experimental results show that the improved convolution neural network model has higher peak signal-to-noise ratio and structure similarity, better denoising ability, better visual effect and better robustness than the deep convolution neural network model.

The network traffic prediction is important for service quality control in computer network. The performance of the traditional prediction method significantly degrades for the burst short-term flow. In view of the problem, this paper proposes a double LSTMs structure, one of which acts as the main flow predictor, another as the detector of the time the burst flow starts at. The two LSTM units can exchange information about their internal states, and the predictor uses the detector’s information to improve the accuracy of the prediction. A training algorithm is developed specially to train the structure offline. To obtain the prediction online, a pulse series is used as a simulant of the burst event. A simulation experiment is designed to test performance of the predictor. The results of the experiment show that the prediction accuracy of the double LSTM structure is significantly improved, compared with the traditional single LSTM structure.

Hydroxyapatite/wollastonite (HA/WS) composite films on titanium alloy were prepared by pulsed laser deposition, and their bioactivity was studied. The dissolution and precipitation behaviors of the films were evaluated by soaking in simulated body fluid (SBF), and the osseointegration ability was evaluated by in vivo test. In the early soaking stage, the dissolution action will dominate, thus resulting in the gradual disappearance of the smooth spherical feature of the particles. After 7 days of soaking, new precipitates were observed which indicates that reprecipitation reaction dominates, and the surface was almost completely covered by new precipitates after the film was soaked for 28 days. The in vivo test showed that the composite films have excellent osseointegration ability. When the sample was embedded in the shin bone of rabbit for 3 weeks, a good combination of bone tissue and implant was achieved, and after embedding for 6 weeks, osteoblasts were observed between the bone tissue and implant.

The traditional distribution network is gradually evolving into the cyber physical distribution system (CPDS) to suit the new characteristics of the distribution network. Distribution network plays an important role of risk source and vulnerable sector. Therefore, it is necessary to do some research on the reliability assessment for CPDS. The key factors of reliability assessment for the distribution network mainly including network components, cyber medium, network topology are firstly analyzed. Reliability assessment index is then summarized in terms of traditional physical system, common cyber system and the CPDS from extensive literature. This is followed by a review of reliability assessment methods in CPDS, which is mainly categorized into two aspects. Finally, the future research emphases are discussed.

The microstructure, texture, tensile strength, and corrosion behavior of Al–Mg–Sc–Zr alloy at different annealing temperatures were investigated using SEM, TEM, XRD, and dual potentiostat techniques. Results show that in the process of alloy homogenization annealing, the Al–Mg–Sc–Zr alloy is able to precipitate spherical particles of Al3(Sc, Zr) with a diameter of about 10 nm and a lattice constant of 0.41 nm, which can pin dislocation, hinder grain boundary movement, and suppress recrystallization. Moreover, the dislocations move to the grain boundaries during the annealing process, leading to the formation of dislocation walls. Remarkably, the sub-crystals are also formed as the grain boundaries parallel to {101}, and move to become parallel to {111}. The texture mainly consists of copper, brass, S, and R, and only a small amount of recrystallization cube texture. Furthermore, under the influence of the microstructure and texture, the strength of the alloy decreases, the plasticity increases, and the corrosion resistance first increases and then decreases. The optimal mechanical properties and corrosion resistance were obtained when the annealing was done at 300 °C for 1 h.

Wollastonite (CaSiO 3 ) ceramics with various Na 2 O contents (0, 5, 10, 15 and 20 mol%) were successfully prepared by sintering sol–gel derived precursors. The ceramics are composed of β-CaSiO 3 . With increasing Na 2 O content, Na 2 Ca 2 Si 3 O 9 , Na 4 Ca 4 Si 6 O 18 and Na 2 CaSi 3 O 8 are observed. The particle size distribution obeys the normal distribution. Na 2 O decreases the total pore volume of wollastonite powder, and increases the apparent porosity of wollastonite ceramic block. Na 2 O increases the bending strength of wollastonite, and the elastic moduli of all ceramics match that of cancellous bone of human body. The thermal expansion coefficients (TECs) of the ceramics are all close to that of titanium alloy (Ti6Al4V). The degradation rate is increased with increasing Na 2 O content. All samples show the ability of apatite induction in simulated body fluid (SBF) solution.

Ceramic coatings were deposited on 2A12 aluminum alloys using micro-arc oxidation (MAO) technology in CH3COONa-Na2WO4 electrolyte. The MAO process was studied by recording the current-time curve. The influences of Na2WO4 concentrations on the coatings in CH3COONa electrolyte were investigated. The results show that the Na2WO4 concentrations affect the MAO process and performances of the coatings directly. Na2WO4 in excess is harmful for the formation of Al2O3 in this electrolyte. The corrosion resistance was enhanced with the decrease of Na2WO4 concentration.

The bioactive coatings were prepared by laser cladding CaO–ZrO2–SiO2 system coatings on titanium alloy (Ti6Al4V). The cross-section morphologies of the coating are cellular crystal and cellular-dendrite structure. With the increase of ZrO2 content, the structure becomes coarse. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. When 5 mol% ZrO2 was added, CaZrO3 appears. With the increase of ZrO2 content, ZrO2 appears and CaO disappears. The surface of these coatings are coarse, accidented and partial porous. After soaking in simulated body fluid (SBF), apatite is formed on the coating surface.

To solve the lack of strength of bulk biomaterials for load-bearing applications and improve the bioactivity of titanium alloy (Ti–6Al–4V), CaO–SiO2 coatings on titanium alloy were fabricated by laser cladding technique. The effect of CeO2 and Y2O3 on microstructure and properties of laser cladding coating was analyzed. The cross-section microstructure of ceramic layer from top to bottom gradually changes from cellular–dendrite structure to compact cellular crystal. The addition of CeO2 or Y2O3 refines the microstructure of the ceramic layer in the upper and middle regions. The refining effect on the grain is related to the kinds of additives and their content. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. Y2O3 inhibits the formation of CaO. After soaking in simulated body fluid (SBF), the calcium phosphate layer is formed on the coating surface, indicating the coating has bioactivity. After soaking in Tris–HCl solution, the samples doped with CeO2 or Y2O3 present a lower weight loss, indicating the addition of CeO2 or Y2O3 improves the degradability of laser cladding sample.

This work is based on microstructural characteristics of Ti-B4C-C laser alloying composite coatings on Ti-6Al-4V alloy in nitrogen protective atmosphere. Test results indicated that laser alloying of Ti-B4C-C pre-placed powders on titanium alloys substrate can form ceramics reinforced hard alloying coatings, which increased the micro-hardness of the substrate. Test results also indicated that the Ti(CN) phase that was formed in situ in the upper coating was undeveloped dendritic, and thus reduced the possibility of crack formation in alloying coating. Moreover, the TiB and TiC phases were produced in alloying coating, which corresponded to its (210) and (220) crystal planes, respectively.

Ceramic coatings were prepared on ZK60 magnesium alloy in electrolyte with different concentration ratio of calcium and phosphorus (Ca/P) by micro-arc oxidation (MAO) technique at constant voltage. The microstructure, phase composition, elemental distribution, corrosion resistance, and adhesion of the coatings were investigated by scanning electron microscope (SEM), X-ray diffractometer (XRD), energy-dispersive X-ray spectrometry (EDS), electrochemical workstation, and scratch spectrometer, respectively. The coating biocompatibility was evaluated by in vitro cytotoxicity tests and systemic toxicity tests, and the bioactivity and degradability were evaluated by simulation body fluid (SBF) immersion tests. SEM shows that pores with different shapes distribute all over the coating surface. The adhesion and thickness of the coatings increases with increasing Ca/P ratio of electrolyte. The in vitro cytotoxicity tests and systemic toxicity texts demonstrate that the coatings have no toxicity to cell and living animal, which show that the coatings have excellent biocompatibility. XRD analysis shows that bioactive calciumphosphate (CaP) phases such as hydroxyapatite (HA, Ca10(PO4)6(OH)2) and calcium pyrophosphate (CPP, Ca2P2O7) are induced in the immersed coatings, indicating that the MAO coatings have excellent bioactivity. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 1574–1586, 2012.

In this study, the influence of YPSZ/CeO2 on the surface performance of the laser-cladded composites was firstly researched. Laser cladding of the Fe3Al/Co42B + YPSZ/CeO2 pre-placed powders on Ti–6Al–4V alloy can form the composite coating, which increased the wear resistance of the substrate. With addition of 20 wt.%TiC, the longevity of the molten pool decreased, leading to the decreasing of the growth time of the precipitates and the content of CoTi, TiNi, AlNi, Ti3Al and TiB phases. The addition of 20 wt.%TiC did not improve the tribological properties of the Fe3Al/Co42B + YPSZ/CeO2 laser-cladded composite coating.

Ti 3 Al–matrix composites were prepared by laser cladding of the Al 3 Ti/TiB 2 /Al 2 O 3 pre-placed powders on the Ti–6Al–4V alloy, which can improve the wear resistance of the substrate. With addition of the proper content of RE oxides (nano-Y 2 O 3 ), this composite coating exhibited finer microstructure and better wear resistance. Nevertheless, excessive RE oxides could lead to the production of the micro-crack, and also decrease the temperature of the molten pool leading to the present of the un-melted TiB 2 block, which can significantly decrease the wear resistance of this composite coating.

Bioactive glass and glass-ceramics in the system CaO–MgO–SiO 2 –P 2 O 5 have been prepared by the sol–gel and high temperature sintering techniques. The obtained samples were characterized by thermogravimetric and differential thermal analysis (TG/DTA), N 2 -adsorption measurement, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). In vitro bioactivity tests were also conducted in simulated body fluid (SBF). The studies of crystallization kinetics under non-isothermal conditions showed the activation energy for crystallization to be 381 kJ/mol and the crystallization mechanism gradually changed from three-dimension growth to two-dimension crystallization with the increase of heating rate. Sintering temperature had great influence on the samples texture and structure. In addition, the apatite-formation on glass and glass-ceramics was confirmed by in vitro tests, and crystallization decreased the samples bioactivity.

This paper tackles a new challenge in abnormal electricity detection: how to promptly detect stealing electricity behavior by a large-scale data from power users. Proposed scheme firstly forms power consumption gradient model by extracting daily trend indicators of electricity consumption, which can exactly reflect the short-term power consumption trend for each user. Furthermore, we design the line-losing model by analyzing the difference between power supplying and actual power consumption. Finally, a hybrid deep neural network detection model is built by combining with the power consumption gradient model and the line-losing model, which can quickly pin down to the abnormal electricity users. Comprehensive experiments are implemented by large-scale user samples from the State Grid Corporation and Tensorflow framework. Extensive results show that comparing with the state-of-the-arts, proposed scheme has a superior detection performance, and therefore is believed to be able to give a better guidance to abnormal electricity detection.

In order to reduce the non-technical loss and reduce the operating cost of the power company, an abnormal power consumption detection algorithm is proposed. The algorithm includes feature extraction, principal component analysis, grid processing, local outliers, and so on. Firstly, we extract several feature quantities that characterize the user's power consumption pattern, and map the X users to the two-dimensional plane by principal component analysis. Data visualization and easy to calculate local outliers, and grid processing techniques to filter out data points in low density regions. The algorithm is used to reduce the number of training samples in the power user data set, and to output the anomalies and probabilities of all users' behavior. The experimental results show that the use of the sorting only need to detect the anomaly of a few users can find a large number of abnormal users, significantly improve the efficiency of the algorithm.

HA coatings were deposited on Ti–6Al–4V alloy substrate using the sol–gel technique. Various heat treatments were carried out and the subsequent effect of heating rate on the resulting coatings was also investigated. The sol–gel derived coatings were studied by X-ray diffraction, electronic probe microanalysis and scratch tester. The results show that the heating rate greatly influences the morphologies, the composition and the adhesion strength of resulting coatings. Under the slow heating rate, the coatings are characterised by high phase purity, compact lamellar structure and less cracks on the surface. Moreover, the scratch test results indicate that the adhesion strength of coatings with slow heating rate is higher than that of coatings with rapid heating rate.

Because of its excellent ferroelectric properties including piezoelectricity, thermoelectricity and photoelectricity, the lead-based titanate ferroelectric thin films have been widely used in the high-tech fields such as microelectronics, optoelectronics, integrated optics and microelectro-mechanical system. As a significant technique in preparing thin films, the sol–gel method has achieved great success in preparing the lead-based titanate ferroelectric thin films. In this paper, the sol–gel fundamental, deposition process and the advantage of sol–gel technique in fabricating ferroelectric thin films were concluded. The materials selection, ferroelectric properties, application fields of lead titanate, lead calcium titanate, lead zirconate titanate, some other lead-based titanate thin films by sol–gel were reviewed, and the influencing factors on the properties of ferroelectric films were discussed.

HA bioceramic coatings were synthesized on titanium substrate by laser cladding using cheap calcium carbonate and calcium hydrogen phosphate. The thermodynamic condition for synthesizing HA was calculated by software Matlab 5.0, the microstructure and phase analysis of laser clad HA bioceramic coatings were studied by electron probe microanalyser (EPMA), X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The theoretical results show that the Gibbs free enthalpy for the synthesis of HA phase is satisfied, and the presence of HA phase in the clad coatings was then further verified by XRD and the selected area diffraction patterns. When the laser power is 600W and the scanning speed is 3.5mm/s, the compact HA bioceramic coatings were obtained, which have cellular dendritic structure and consist of the phases of HA, alpha-Ca(2)P(2)O(7), CaO and CaTiO(3).

Hydroxyaptite (HA) films were prepared by pulsed laser deposition from two kinds of targets using a KrF excimer laser at a substrate temperature of 575 °C. The characterization of films was studied by an electron probe microanalyzer, scanning electron microscopy, atomic force microscopy, glancing angle X-ray diffraction, and Fourier transform infrared spectroscopy. In vitro tests were performed to study the biocompatibility of the films. The results showed that the films were crystalline and there was a substitution of CO32− for PO43−. In vitro tests showed that with increased immersion time, the crystallinity of films became low, and the Ca/P ratio of films decreased first and then stayed at a stable value which is lower than that of the theoretical value of hydroxyapatite. The bands of new precipitated bonelike apatite were the same as with the original HA films, which indicated that the films had a good biocompatibility. The sintered temperature of the target had a small effect on the microstructure, w...

Glass of the Si – Na – Ca – P system has been synthesized by normal melting and annealing technique. The obtained glass powders and annealed blocks were showed to be amorphous by X-ray diffraction (XRD). The thermal properties of glasses were analyzed by differential scanning calorimetry (DSC), it showed that the glass transformation temperature (Tg) was 556.3°C. The behavior of annealed glass discs in simulated body fluid solution (SBF) was studied in polyethylene containers at a constant temperature of 37°C for different time up to 14 days. The changes in the surface morphology and composition were observed by electronic probe microanalyzer (EPMA) associated with energy dispersive spectroscopy (EDS). Glass surface changed quickly as soon as immersion took place, and after longer soaking time, it showed different superimposed internal and external layers, which were identified as SiO 2-rich and CaO – P 2 O 5-rich layers, and on the external layer, spherical particles were also discovered.

The yttric calcium phosphate (CaP) coatings were in situ prepared on pure titanium substrate by laser cladding. The morphologies and phases constitution of CaP coatings were studied by electron probe microanalysis, X-ray diffraction and so on. The bonding state between the coating and the substrate is fine metallurgical combination, and the addition of yttria can fine the structure and increase the tensile strength of the coatings. The X-ray result shows that the coating is composed of the phases of HA, α-Ca 2 P 2 O 7 , β-Ca 2 P 2 O 7 and CaTiO 3 .

Glass of the Si–Na–Ca–P system has been synthesized by normal melting and annealing technique. The obtained glass powders and annealed blocks were showed to be amorphous by X-ray diffraction (XRD). The thermal properties of glasses were analyzed by differential scanning calorimetry (DSC), it showed that the glass transformation temperature (Tg) was 556.3°C. The behavior of annealed glass discs in simulated body fluid solution (SBF) was studied in polyethylene containers at a constant temperature of 37°C for different time up to 14 days. The changes in the surface morphology and composition were observed by electronic probe microanalyzer (EPMA) associated with energy dispersive spectroscopy (EDS). Glass surface changed quickly as soon as immersion took place, and after longer soaking time, it showed different superimposed internal and external layers, which were identified as SiO2-rich and CaO–P2O5-rich layers, and on the external layer, spherical particles were also discovered.

Inspired by the immune theory and multi-agent systems, an immune multi-agent active defense model for network intrusion is established. The concept of immune agent is introduced, and its running mechanism is established. The method, which uses antibody concentration to quantitatively describe the degree of intrusion danger, is presented. This model implements the multi-layer and distributed active defense mechanism for network intrusion. The experiment results show that this model is a good solution to the network security defense.

Metallic biomaterial, as a kind of composite materials, has been applied extensively in medical field due to its mechanical advantages and biological affinity. The sol–gel technique, as a new method to prepare the hydroxyapatite (HA) coating, has a lot of advantages. Therefore, the principle, characteristic and the researchment status of sol–gel technique are introduced. And the structure, characteristic and bioactivity of the HA coatings prepared by this method, as well as the influence of various parameters are discussed. Finally, the applied prospects of sol–gel technique in medical field are discussed.

The low bonding strength between plasma sprayed hydroxyapatite (HA) coatings and substrates is one of the problems, which should be solved. In this paper, the as-sprayed HA coatings were retreated by laser remelting. The microstructure and element analysis in coatings were studied by electron probe microanalyzer (EPMA) and the accessory of energy spectrum analyzer. The results show that the bonding state can be improved greatly after laser remelting and it is a metallurgical combination between transition layers and substrates. Generally, with the increase of laser power and the decrease of scanning speed, the bonding state between the surface and transition layer will be improved much more, but the value of Ca / P ratio will deviate much more from 1.67. In this experiment, the optimum technological parameter is that the laser power is 600 W and the scanning speed is 11.2 mm/s.

Pulsed laser deposition (PLD), which is a novel technique in producing thin films in the recent years, shows unique advantages for the deposition of ferroelectric films. Effects of technical parameters on the pulsed laser deposited ferroelectric films, including substrate temperature, oxygen pressure, post-annealing, buffer layer, target composition, energy density, wavelength, target-to-substrate distance, and laser pulse rate, are systematically reviewed in order to optimize these parameters. Processing-microstructure-property relationships of ferroelectric films by PLD are discussed. The application prospect is pointed as well.

It is thought that the PEO (plasma electrolysis oxidation) coatings are difficult to be prepared on the cast Al – Si alloys because these alloys contain lots of pure silicon phases. In the present study, oxide coatings with a thickness of about 10 μm were deposited on the substrate of the ZL109 Al – Si alloy by a PEO treatment. XRD showed that the phase composition of the coating was γ- Al 2 O 3. SEM showed that the coating surface was porous, and the pore diameter was in the range of 1–5 μm. The cross-section view by EDS indicated that the coating matrix is quite dense, and there are few defects. Phosphorus from the applied electrolyte could be incorporated into the coating during the PEO process. A transitional zone with a thickness of about 3 μm was observed on the interface between the coating and substrate, and a high adhesive strength was expected. The average hardness of the coating was 576 HV0.025, which was 7.2 times higher than that of the substrate. High alloy element content of the substrate seems to have no remarkable and adverse influence on the structure and composition of the PEO coating.

Pulsed laser deposition (PLD) is being investigated as an alternative technique to prepare hydroxyapatite coatings. In this research we studied the microstructure and phase composition of the PLD hydroxyapatite films. The surface morphology of the films is composed of droplets for which size ranges from hundreds of nanometers to a few micrometers. The cross-sectional morphology of the films shows that the films adhere to the substrate well and there are no microcracks, pores and other defects between substrate and films. The X-ray diffractometer results show that the deposited films are amorphous and the post heat treatment films consists of crystalline HA and TiO 2.