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In order to obtain the effect of second phases on Charpy impact energy and crack propagation behavior of Hastelloy N sheet, Charpy notched impact toughness test have been accomplished with different directions (RD, ND) of V-notch after solution treatment. The fracture morphology and microstructure are observed by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). It is shown that the dominant second phases in Hastelloy N after solution treatment includes molybdenum-riched Ni-Mo phase, which dissolve some elements such as chromium, silicon and ferrum, and a few carbides. The Charpy impact energy of sample 2# (RD) is 225J, almost twice as much as sample 1# (ND). Based on the reconstruction of morphology and distribution of second phases, the mechanism for effect of second phases on crack propagation behavior is discussed. The islands of second phase particles modify the stress triaxiality state, resulting in the propagation path of crack in 2# is totally different from that in 1#.

UO2 fuel pellets may be swelling and recrystallization during irradiation. Density, dimension and distribution of pores are main factors to induce irradiation swelling, especially the size distribution of pellet pores plays an important role. 4×4-4 fuel assembly was a high performance fuel assembly which was self-designed and manufactured, the average burn-up of the fuel assembly was 42GWd/tU.For studying the effect of irradiation on pore modality, the specimens of irradiated UO2 fuel pellets were taken from 4×4-4 fuel assembly after dismantling, microscopic structure and distribution of pores for UO2 fuel assembly by scanning electron microscopy were studied in this paper. The results showed that there were many cracks in fuel pellets, most micro-cracks were transgranular crack. The release rate of fission gas with burn up were augmentation, which was consistent with the porosity of diversity burp up fuel rod. Pores were distributed non-uniformly in irradiated fuel pellets, gathered at local area and more obvious connectivity of pores. The size of pores after the irradiation was between 0.2~1.2 μm, and mostly distributed at 0.3μm ~0.6 μm; The pores at grain boundary of two adjacent grains was less, the pores at grain boundary were distributed by the way of triangle or quadrilateral. The size of pores was increased than pre-irradiation, but ratio of pores and density of pores were decreased obviously, the phenomenon of irradiation densification was occurred in fuel pellets after irradiated. Recrystallization and Rim structure effect were not found.

With the slope unstable rock masses of a stope in Longsi mine, Jiaozuo City, China as the target, we computed and analyzed the stability of unstable rock masses using a limit equilibrium method (LEM) and a discrete element strength reduction method (SRM). Results show that the unstable rock masses are currently stable. Under the external actions of natural weathering, rainfall and earthquake, unstable rock mass 1 was manifested as a shear slip failure mode, and its stability was controlled jointly by bedding-plane and posterior-margin steep inclined joints. In comparison, unstable rock mass 2 was manifested as a tensile-crack toppling failure mode, and its stability was controlled by the perforation of posterior-margin joints. From the results of the 2 methods we find the safety factor determined from SRM is larger, but not significantly, than that from LEM, and SRM can simulate the progressive failure process of unstable rock masses. SRM also provides information about forces and deformation (e.g. stress-strain, and displacement) and more efficiently visualizes the parts at the slope that are susceptible to instability, suggesting SRM can be used as a supplementation of LEM.

The polytetrafluoroethylene (PTFE) hollow fiber membranes were prepared through a cold pressing method including paste extruding, stretching and sintering in this study. Membrane vacuum regeneration technology (MVR) was developed as a novel regeneration technology for regeneration of the absorbent. The membrane structures of the PTFE hollow fiber membranes were investigated. The mixture of N-methyldiethanolamine and piperazine was selected as the absorbent. The PTFE hollow fiber membranes were used for regeneration through vacuum membrane regeneration technology. The CO2 regeneration flux and regeneration ratio increased with the increase of the regeneration temperature and the CO2 loading. The regeneration pressure was negative to the regeneration flux and regeneration ratio. When the flow rate of the rich solution increased, the regeneration ratio decreased and CO2 regeneration flux increased significantly.

The Nb2AlC powders were synthesized by high temperature solid state reaction method ,in which, the mixed powders of niobium (Nb), aluminum (Al) , graphite (C) were used as raw materials in an atomic ratio of 2.0:1.1:1.0, respectively. And the heating temperature was adjusted in a range of 1600–1650°C in order to investigate the effects of different preparing conditions on the synthesis of Nb2AlC .The phase composition and morphology of the products were analyzed by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) respectively. The results indicated that all the XRD peaks can be indexed as Nb2AlC with improved crystallization at 1610°C.And the SEM photographs show that the products are layered morphology.The reaction mechanism of Nb2AlC synthesis was also studied.

A local adaptive neighborhood model is proposed in this paper in order to deal with the mistake judgment in the existing scanning beam point cloud denoising algorithms. Such a model regards larger curvatures as the potential noises, can select angle thresholds of noise points and the median values of filtering windows adaptively, so as address the issues of mistake judgment and missing judgment of the point clouds denoising algorithms with different curvatures. The adaption theory in the angle threshold denoising algorithm classifies the noise points and data points. Therefore, it can ensure the smoothness in low frequency, and as well keep the high frequency characteristics. The new method improves the accuracy of median filtering, prevents the diffusion of noise, remove noises effectively while preserving sharp features, and avoid fuzzy data margin.

Meteor burst communication is an important communication mode for a number of possible civilian and military applications. This paper proposes a channel modeling and simulation based on OPNET for meteor burst communications. Analyzing the characteristics of underdense meteor burst channel, the multi-layer node models of master station and slave station are presented to create practical simulation scenario of meteor burst communications. The simulation processes of half-duplex communication as well as full-duplex communication are designed to execute simulation. The results demonstrated that the channel model based on OPNET is consisted with meteor burst communication very well, and full-duplex communication is better than full-duplex communication in effectiveness.

In the big cities, the shield undercrossing metro project has become critical to the safety of the metro, this paper takes the South-North Water Transfer Project shield under traverse Beijing certain subway project for construction background. It makes technical schemes comparison, analyses the deformation law of the existing subway structure and propoes protective measures to prevent the existing subway structure. The analysis showed the following conclusions: in shield undercrossing the metro project, in order to reduce disturbance on surrounding soils and the existing metro structure, we should take the necessary control measures such as grouting and determine the optimum shield parameters; the overall trend of the monitoring results accords well with numerical simulation results; The reason why the actual values and model calculation values has certain deviation is that it is difficult to consider shield parameters such as the pressure of shield thrust, pressures of grouting and so on in numerical simulation.

The tensile experiments were carried out under the condition of different pulse current on pure aluminum to analyze the effect of pulse current on the mechanical property such as tensile strength and elongation on material. The results show that pulse current could improve the mechanical properties and with pulse current the elongation of the aluminum increased to 19.5% and its tensile strength drops to some extent with the increase of electricity. At the same time, the dislocation structure features under different current density are also different. Without pulse current, dislocation is distributed as group unevenly. But when the current density J=8×102A/cm2, dislocation morphology changed into a mass of dislocation cells and moved to the grain boundary. Part of the cell walls formed grain boundary and then small angle subgrain formed. With the increase of current density, dislocation walls are arranged neatly and parallel to each other and at last single dislocation wall will be split into two or more parallel dislocation walls and form structure of striped band.

In this paper, a predictive model has been established for the combat effectiveness of amphibious assault vehicles by the method of supporting-vector regression. It has a good fitting result after trained with the samples. Then this model is used to predict the combat effectiveness of the sample under evaluation. The SVR approach can convert the practical questions into the high-dimensional feature space through non-linear transfer, and construct the linear decision functions in the space to realize the original non-linear decision functions. This approach has its significance for the prediction of combat effectiveness of AAVs.

This paper introduces the design of an airborne pulse Doppler radar jamming system tester. Based on a detailed analysis of the functional structure of the radar-jamming system, we summarize the important failure mode. To achieve fault location and performance testing, we have developed an automatic detector for the radar-jamming system, the device uses a mode of hardware platform and software platform, and it can reach the purpose of fault location by a method of encouraging input and measuring the output of each of the radar-jamming system failure mode individually. The automatic test instrument has the features of simple operation, high degree of automation, real-time, scalable, and actual use of running proves it to reach the required design specifications, the test with good results.

With the development of computer technology, the intelligent technology and the virtual instrument technology is becoming more and more important in the testing field, the radar automatic detection system described in this article concludes virtual instrument system, detection platform and troubleshooting software. The system can individually and comprehensively and quickly check the performance of the equipment for automatic diagnosis, greatly improving the technical support capabilities of the equipment. Functionally, it can be easily expanded and upgraded, with a high value of promotion and application prospects.

In the big cities, any construction nearby the metro structure become critical to the safety of the metro,especially for deep foundation pit engineering.In such case,Pile-anchor supporting system is normally used, however different deformation shape of the supporting wall will bring different deformation of the metro structure.This paper analysed the relations between the pile-anchor supporting system and the nearby metro structures and stated how to control the nearby metro structure deformation through the design of the Pile-anchor supporting system.The analysis showed the following conclusions:If the nearby metro structure is closer to the ground surface, it will be more sensitive to the deformation of the piles-anchor system;Shape 1 & 2 are better to control the metro structure deformation,Shape 3 will result bigger settlement;the metro structure above and in the middle of the foundation bottom level are very much influenced by the deformation of the piles;If the deformation of metro structure exceeds the allowable value, other measures should be considered.

Due to the large and medium-sized cities in our country is more; the urban rail speed is low and the environmental protection high capacity requirements. Each city urban rail structures more or less differences. Especially fastener system is various, even in the same line also exist different deduction system; Because the subway in China fastener system is various and not a fixed is widely used fastener system; The paper gives a simple summary of subway common shock absorber fasteners in China. I hope it can give a reference to researchers on fasteners.

A multi-residue method for determination of pesticide residues in vegetables, using ethyl acetate extraction and determination by means of GC–MSD, is presented. The method includes as many as 27 pesticides such as organophosphorous, organohalogen, organonitrogen and pyrethroids pesticides, which are in common use or forbidden on vegetables in China. After extraction with ethyl acetate, the extract is concentrated and evaporated to dryness and redissolved in ethyl acetate before injection on GC–MSD. The recoveries were obtained in the range 70–100% with 5 exceptions in lettuce and 7 exceptions in cucumber, relative standard deviations between 1.92% and25.39% by means of standard addition to the vegetables blank extracts. The degradation of some pesticides in the 27 was studied by the method developed, the mixture of the pesticides commercial formulations was sparged on the vegetables, then the residues of samples obtained in different time were determined by the developed method. The determination indicated that (all pesticides were used as the instruction): 1.a pesticide, used on different plants, the quantity of the pesticide on the part for people’s dietary differs greatly; 2. some pesticides, degradating slowly and with a large dose, are inappropriate used on vegetables which remain on cropland for a short time. This research does not develop models for pesticides degradation, but provides some data on the safe intervals of the pesticides and a potential method for the study of multi-class pesticides safe intervals on a plant simultaneously.

Belonging to the Bentley Microstation series which work as one of the BIM platforms, the Bentley Power Rail Track shows huge advantages in the railway design for its visibility, high efficiency, advance, reliability and so on. This paper introduces the way to build the digital terrain model, alignments, cross sections, turnouts and to display the three-dimensional model of the railway for the Bentley Power Rail Track 3D railway design software. It provides application preparation for the BIM railway design and achieves the preliminary exploration of BIM applications. Bentley Power Rail Track proves capable of the BIM railway design.

For the design of prestressed concrete sleeper, design methods and standards in different countries are different. America and China design sleeper by the allowable stress method, UIC design by probability limit design method. China has design II-sleeper by the method of reliability, but the theory is not immature so that II-sleeper appeared a lot of cracking problem. In recent years, designing IIIa-sleeper still use the allowable stress method. By contrast of process of designing IIIa-sleeper in China and America, include design load moment, the prestress loss, bearing capacity of structure, test and so on. Get the main difference of designing sleeper in China and America, and the rationality and practicability of different design method.

Prestressed Concrete Cylinder Pipe (PCCP) consists of a steel cylinder lined with concrete, then helically wrapped with a wire and coated with a dense mortar. PCCP has excellent structural properties, so it is widely used in various water-transportation projects around world. This paper presents a review of development of PCCP in China, which was summarized as three stages: the period of exploratory development, the period of cooperativedevelopment, and the period of independent development. The development process of design and production technique, the application in China, the construction and development prospect of PCCP were made a detailed discussion in each stage.

Wenrui river system in the north of Fanyou is located in Wenzhou city. In recent years, river water quality has been improved by the implementation of ecological water diversion with the phenomenon of large area of black smelly basically eliminated. But there is still no fundamental improvement in river water environment. In this paper, sluice scheduling, scheduling of water supply and optimized control scheme is studied based on the one-dimensional river network model, on the basis of current situation of ecological operation, through analyzing the characteristics of river water system in north of Fanyou, water source and the distribution of main control sluice. It is turned out that water quality of Wenrui river system in north of Fanyou cannot be comprehensively improved by ecological water diversion and can only be targeted to the important areas and key rivers, due to the large area, complex river net and limited ecological water supply. Pollution reduction is the most fundamental way to improve river water quality. But currently, on the premise of difficultly cutting down complete pollutions, river water quality can be improved to a certain extent by ecological water diversion with Puzhou sluice as the main control sluice, combined with other sluices for joint scheduling. In the future, if pollution load can be reduced and enough water supply can be guaranteed, river water quality can reach class II or III in the key areas along the Ou River and river water in other areas also has different degrees of improvement.

Against the sticking patch design problems of pass damage of aircraft skin repair, by using the calculation method of mechanical analysis, the stress analysis of pass damage is completed. The calculation methods are used quantitatively to determine the sticking patch dimension of pass damage repair, which is compared with analysis sticking patch design method calculated by the repair empirical equation of aircraft skin of Airline Company. The reason of error is analyzed and the measure to correct empirical equation method is put forward. The optimization of the critical parameters of pass damage empirical equation is completed.

7A52 aluminum alloy was welded by using 5356 welding wire added Sc, Zr and Er. Microstructure of the welding joint was observed by using optical microscope (OM). Bending property was tested by bending tester. The results demonstrated that, compared to employ traditional 5356 welding wire, the grains in welding zone (WZ) were much finer; The grains in fused zone (FZ) nucleated and grew from the matrix; The grain size along heat affected zone (HAZ) dercearsed gradually.The welding joint prepared by using 5356 welding wire added single 0.3%Sc possessed maxium face bending strength. The welding joint fabricated by using 5356 welding wire added compond 0.1%Sc+0.2% Er possessed maxium rear bending strength. The fine isometric crystal and isometric dendrite generated at the welding zone when the new type 5356 wire added gingle Sc or compound Sc+Er was employed, which make the welding joint represent excellent bending property, respectively.

It is studied that the growth of entire functions defined by multiple Taylor series by means of Polar coordinates, and established two sufficient and necessary conditions.

SrMoO4:Eu3+ micro-spheres with well morphology were fabricated by a one-step and template-free ultrasonic spray pyrolysis method using strontium nitrate and ammonium molybdate as precursors. The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectra (PL). The XRD results indicate that all the XRD peaks can be indexed as SrMoO4 with a pure tetragonal scheelite structure. The SEM photographs show that the sample particles are spheres with regular spherical shape. The excitation and emission spectra demonstrate that the phosphors could be excited effectively by the ultraviolet light with wavelength 394 nm or visible blue light with wavelength 466 nm, and the highest emission peak locates at 615 nm.

For the high-speed machining aero engine casing hole, according to the principle of metal forming and the characteristic of metal cutting plane strain, with selecting some key physical factors of the cutter - chip contact friction and abrasion model, the Cartesian orthogonal cutting model of aero engine casing hole was established by using the Deform, a sort of finite element analysis software. With taking cutting temperature for preferred aim of the cutting parameters, select the appropriate cutting parameters, the aim of aero-engine casing high-speed (cutting speed up to 700m/min) cutting has been achieved by simulation, and the feasibility of the cutting process was researched and confirmed in theoretically by analyzing the cutting force, cutting temperature and tool wear condition.

According to the comprehensive performance of electric glass regulator detection process, the installation screw hole of the glass regulator often was damaged when electric glass regulator was installed, so the flexible clamping mechanism of floating force was is designed, to fix and clamp the electric glass regulator, and all flexible clamping mechanism was emulated and analyzed, the results show that the flexible clamping mechanism is safe and reliable, so the theoretical basis was provided to optimize and design the online comprehensive performance equipment in the further.

The pomponlike CaMoO4:Eu3+ red phosphors were synthesized via a ethylene glycol (EG)-mediated hydrothermal method in the presence of urea at 140 °C for 1 h. The structure, morphology and luminescent property were characterized and investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL). The results show that the Eu3+-doped CaMoO4 micropompons were well-crystallized and assembled by nanosheets. The products display a strong red emission under near ultraviolet (UV).

Requirement is the cornerstone of the project,A good requirements specification is the key to the success of the project, requirements specification content from the user's requirements. How to accurately, effectively elicitation of the user's requirements This paper on the different application system of nuclear power enterprise used by the methods in requirements elicitation were discussed. By choose the correct method can effectively elicitation of the user's requirements.

The feature extraction and detection problem of network information abnormal behavior was researched in this paper. The network attack tended to ambiguity in hidden, and the abnormal behavior of network information is referred as a data signal series, and it was existed in the network information space with strong interference. Traditional detection method was hard to detect the abnormal signal. On the basis of fractional Fourier transform (FRFT), an improved abnormal behavior feature detection algorithm of network information was proposed. The properties such as energy gathering and noise suppression of 4-order cumulant slice were taken in advantage. In the post processing of fractional Fourier transform detection, the post processing operator of 4 order cumulant was introduced in the detection algorithm, the post energy was gathered in the fractional Fourier domain, the signal accumulation was likely to be increased, and the interference noise could be restrained effectively. Simulation results show that the improved algorithm has perfect noise suppression performance, and it can detect and extract the abnormal behavior feature in the network space to maximum. The detection performance is improved greatly, and the research result can be applied in the network information warfare and network security areas.

A novel mutiscale and directionally adaptive image transform called contour based directionlet tansform is presented. Directionlet transform (DT) has shown its charming performance in image processing, but it has scrambled frequencies. Laplacian Pyramid is employed here to separate the low frequencies before applying DT for avoiding the drawback. And an adaptive threshold algorithm is proposed for denoising. Numerical experiments are performed to assess the applicability of the proposed method. The obtained results show that the proposed scheme outperforms Wavelet and Directionlet transforms in terms of numerical and perceptual quality.

This paper develops a novel distributed jointly sparse optimization algorithm to recover the sparse signal, in which the joint sparse structure is used to improve the quality of recovery. In distributed networked multi-agent system, each agent collects measurement vectors and aims to recover its own sparse signal collaboratively in a distributed manner. We propose to use the factored gradient approach to calculate the solution iteratively, and introduce a energy vector of the current estimates as the consensus constrain which is updated by inexact consensus optimization for its distributed implementation. This algorithm does not require excessive data transmissions from distributed agents to fusion center, which reduces communication overhead and the computational complexity of the agents. Simulation results demonstrate that the proposed distributed algorithm has strong recovery performance and can reach global convergence as well as fast convergence rate.

Benzaldehyde was produced from oxidation of cinnamaldehyde by hydrogen peroxide in propylene glycol in the presence of sodium bicarbonate. Protic solvent demonstrated high selectivity and the yield of benzaldehyde could reach up to 82% in propylene glycol. The effect of solvent on the selectivity was attributed to hydrogen bond interaction between the oxidation intermediate epoxide and the solvent.

Based on the theories of the method of the finite element and the interaction between beam and rail, the common railway bridge: the continuous girder bridge and the simply supported girder bridge as an example, set up the integration of the calculation model of the line-bridge-pier on the continuous welded railway bridge, through the calculation software of Bridge Continuously Welded Rail (BCWR2010), the regular pattern of the effect of the bending force and the regular pattern of the longitudinal displacement distribution of the rail and bridge are analyzed.

Keywords: ion nitriding furnace cooling system vacuum system Abstract. About fuction of vacuum plasma nitriding furnace cooling system, and its design and calculation of main parts, in particular control of water consumption. The cooling water system have been set into the water flowing through the four heat shield, and gradually take the heat, then the coolant out by outlet pipe. Cooling water flows through layers of insulation to varying degrees of cooling, to ensure that each level of temperature, precise calculation of water flow can only be guaranteed to ensure the maximum water savings and cooling the furnace down. This article provide the basis for vacuum furnace cooling system design in the future.

In this paper, the method based on the testing of the Fourier transform near infrared (NIR) spectra is proposed to identify natural bamboo fibers and flax fibers. The discrimination models between natural bamboo fibers and flax fibers are established by means of Ward’s algorithm and Hierarchical Cluster Analysis after the first derivative and vector normalization pretreatment. The verification results indicated that these two kinds of fibers could be classified into two separated groups for the identification and the near infrared spectra model is high accuracy.

In this article, we propose the matching pursuit algorithm of combinatorial optimization based CGLS and LSQR. We use non-negative matrix factorization for measuring discrepancy of solution sequence between CGLS and LSQR, and represent combinatorial optimization based CGLS and LSQ to choose optimal solution sequences. The experiments indicate our method is extended to the case where target signal has been corrupted by noise, it demonstrate perfectly recovery ability of signal with noise.

In this paper, pure metals aluminum was used to study the effects of pulse current on their mechanical properties. The results showed that the pulse current caused the tensile strength of metals to decline remarkably. The elongation of metal rose and was enhanced with increasing current density. At the same time during the performance of plastic deformation, pulse current heating effect could change the mechanical property to some extent and can not be ignored.

A direct, efficient method for the problem of epipolar rectification in the uncalibrated casewas proposed. The method was based on minimizing a measure ofdistortion, by introducing anepipolar distance transform. The transform converted image intensity values to a relative locationinside a planar segment along the epipolar line, so it was robust to noises. The ratio of the distancesbetween two matching points in the epipolar lines was theoretically proved invariant to an affinetransformation for planar surfaces. To calculate the relative rotation between both cameras, thealgorithm was decomposed into three-steps to limit the distortion. Results show that the new measureis more appropriate for image rectification, and the three-step algorithm has obtained an accuracycomparable result both in estimation error and visual effect, especially when the initial epipolar linesare far from horizontal.

An integrated design method of the compliant linear positioning device (CLPD) was researched, which was composed of a compliant guide mechanism and two electromagnetic actuators. Typically, the actuators are designed after the compliant mechanism, which may make it more complex to improve the performances of the CLPD. With the utilization of the multi-physics co-simulation technology, established a parametric multi-physics finite element model (MFEM) of the CLPD including the compliant linear guide mechanism and the electromagnetic actuators simultaneously in the COMSOL environment. Proposed the constraints of the dominant parameters, based on the analysis of their influence on the characteristics of the CLPD. Then an integrated optimizing design strategy of the CLPD was put forward. According to the strategy, a two degree of freedom long-range linear compliant mechanism and its matching actuators were designed. The experimental results showed the performance of the designed CLPD, which validated the design strategy.

In a closed pulverized coal preparation system, a special device must be installed to vent flames and pressure during unexpected dust explosions. A vent flame arrestor is a key element in this device, which helps prevent a dangerous second explosion by venting flames. Traditional vent flame arrestors are designed with mounting metal fiber or rock fiber on both the sides and the top of the arrestor to cool dust flames and arrest burning dust during an explosion. This type of arrestor is widely used, but their application is still problematic, even for St1 dust at low reduced pressure (Pred). To solve these problems, we designed two types of flameless venting devices. The first is intended for St1 dust explosion venting at Pred 0.07 MPa, and was modified from an original device by adopting a labyrinth-like structure in the interior space to successively reduce the strength of the dust flame. The second is intended for St1 dust explosion venting at 0.07 < Pred 0.18 MPa, and was modified from the first type by adding a special suppressant in the interior space to make the dust flames cooler than the ignition point of the dust. Our experiments confirmed that our designs yield improved efficiency of flameless venting devices, leading to safer vent flame arrestors.

In this paper, pure metals Ti and Ta were used to study the effects of impulse current on their mechanical properties. The results showed that the impulse current caused the tensile strength of the two metals to decline remarkably. The elongation of metal Ta rose and was enhanced with increasing current density. But as for metal Ti, the elongation hardly rose. Theoretical analysis suggested that the impulse current had little apparent effect on HCP metals, for it had less slip systems; however, it had obvious effects on the elongation of BCC metals, for they had more potential slip systems. The transmission electron microscopy (TEM) observations showed that crystal microstructure of the two metals had not changed significantly.

In this paper, we present a new nonlinear ternary interpolatory subdivision scheme which has the properties of convexity-preserving, circle-preserving and the limit curve iscontinuous. In each subdivision step, the newly generating points will be on the circle determined by the interpolatory point and its adjacent points. Numerical examples show that this algorithm is simple and curves generated by this subdivision scheme are fair curves.

The inelastic response constitutive description of metal material under different stress and wide temperature range is very important in many practical engineering. It can accurately reflect the level of material rate sensitivity and set up a simple and practical strengthening evolution rate. Take No.35 steel as an example; because of the action of load, temperature, time and other factors in its forming process, the creep relation is very important and complex. In view of this situation, the BC-BPNN (Based on Back propagation Neural Network), owing high precision nonlinear fitting ability has and good generalization ability, is applied to the research on creep constitutive relationship of 35 steel. At first, the creep relationship is numerically fitted using testing data of 35 steel; then, the fitting results is compared with the creep testing data. The results show that the applying of BC-BPNN to research on metal creep relationship has a strong practical value.

Cylindrical TiO2nanotubes and hexagonal TiO2nanotubes were obtained in the anodizing process of titanium in fluoride-containing electrolyte. Based on the experimental findings and viscous flow model, a mechanism of self-ordering process of hexagonal cells arrangement for porous anodic TiO2nanotubes (PATNT) is proposed in this paper. The analysis results show that oxygen evolution in the pore bottoms plays an important role in the self-ordering process. Oxide grows around the oxygen bubbles in the pore bottoms, which results in the formation of cylindrical TiO2nanotubes. Volume expansion of TiO2takes place during the anodizing process. Plastic deformation and repulsive force caused by volume expansion are responsible for self-ordering process of PATNT hexagonal cells.

There are several hundred of abandoned oil wells in Jianghan oil field now. They were mainly started to be used in 70-80`s of last century, and mainly closed around 2000. After closure, the soil around the oil wells left uncultivated because of oil pollution, which caused serious waste of soil resource. In the present paper, 135 soil samples were collected from 15 oil well areas. Salinity, pH, petroleum hydrocarbon, heavy metals and some other elements were analyzed. According to the investigation, the soil of Jianghan oilfield showed high salinity, and tended to alkali. Petroleum hydrocarbon is dotted distribution, and some sites showed extremely high content as 24.67%. Some elements containing some heavy metals in Jianghan oilfield exceeded standard values and control samples, which may also be caused by oil exploitation.

The quality and cost of a product rely heavily on selecting suitable engineering materials, and therefore the ability to select the most appropriate material for a given application is the fundamental challenges faced by the design engineer. The general grey relational analysis (GRA) has three weaknesses: (1) weight determination depends only on expert judgments; (2) the qualitative indexes are only simply quantified with exact number; and (3) the general GRA only takes into account the relationship between the imaginarily best material and the candidate materials. The GRA is extended to RGRA, weights are determined by combining subjective and objective weights based on maximum deviation, and the qualitative indexes are fuzzily quantified through trapezoidal fuzzy number (TFN). The illustrative example shows that the presented method enables decision making results to be more reasonable and trustworthy.

To solve the abnormal rail corrugation problem of Beijing Metro Line 4, the track structural parameters comparative tests were carry out in the Metro Line 1,2 and 4. Metro Lines 1 and 2 were chosen based of the Beijing Subway Survey and previous successful experiments. The comparative analysis was based off of rail static geometry, dynamic displacement and the lateral acceleration. The test results proved the stiffness of line4 is weaker than line1,2 and suggestions on steps to prevent and correct the metro rails abnormal corrugation will be formulated.

The bond between concrete and steel is the critical element of reinforced concrete (RC) structures, which directly affects their load carrying capacity and serviceability. Hence the evaluation of bond strength degradation is an essential parameter to predict the residual strength of RC structures affected by reinforcement corrosion. Existing research studies in this field mainly focus on numerical and experimental investigations. Few attempts have been made using analytical approach but there is still a need of reliable model which considers the critical mechanical factors affecting the bond strength of corroded RC structures. This paper presents a simple and realistic analytical model of bond strength degradation by using fracture mechanics combining the action of adhesion, confining pressure and corrosion pressure at steel concrete interface. Finally, the results obtained from the proposed model are examined with published experimental data. The study demonstrates that the proposed analytical model agrees with the experimental data of existing investigations.

This paper proposes a symptom-based reliability analysis method for deteriorating reinforced concrete (RC) structures on the basis of monitored data. The structural flexural resistance due to reinforcement corrosion is selected as a symptom which reflects the deteriorating structural performance. The symptom reliability and remaining service life are then estimated from the Weibull model for the structural flexural resistance development. The results for the numerical study example show the proposed approach is capable of prediction the remaining service life for the deteriorating RC structures subjected to the reinforcement corrosion.

A new algorithm is proposed for digital watermarking by applying complex-valued linear-phase filter banks to low frequency-band coefficients of images in the DCT domain. The watermark is conveyed in the phase spectrum of the subband coefficients. The robustness of the algorithm is examined in JPEG encoding with different qualities and compared with the DFT-based approach. Because only low frequency-band DCT coefficients are applied to complex-valued filter banks, the computational load introduced by the complex-valued filter banks is kept low. The watermark decoding is only accessible to users with the key information, i.e., impulse responses of the complex-valued linear-phase filter banks that designed with time-frequency spread property.

In this paper, non-multiplier approximation of frequency transformation is examined. 2-D frequency response marking filters with sum of powers-of-two (SOPOT) coefficients are designed. The numbers of adders allocated to transformation coefficients are determined in the experiments so that the resulting 2-D filters preserve the stopband attenuation of the original 1-D prototype filters. Experimental results of 2-D wideband FIR filters with low arithmetic operations and computational complexity are presented.