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The microstructural evolution of DD9 single crystal superalloy turbine blade was studied after heat treatment. In comparison to the as-cast microstructures where the sizes of the γ′ precipitates have an obvious difference between the dendritic core and interdendritic regions, the γ′ sizes of the heat-treated microstructures tend to be uniform and more cubic. And in the heat-treated microstructures, the γ′ sizes and the related size dispersion degrees of the dendritic cores are slightly increased, while those of the interdendritic regions are obviously decreased. After all, all the γ′ sizes follow the normal distribution law. With the raise of section thickness, the γ′ sizes tend to increase and the related size dispersion degrees are enhanced during the cooling process after heat treatment, and the γ-γ′ eutectics are dissolved, left little residual eutectics and pores.

In this work, a new type of δ-TRIP steel was designed. The fatigue limit and S-N curve were measured by the fatigue testing machine. The fatigue fracture was observed by the scanning electron microscope (SEM), and influencing factors of fatigue crack initiation were analyzed. The results show that the fatigue limit of δ-TRIP steel is 361MPa, and fatigue cracks are initiated on the surface of the sample. In the initial stage of fatigue crack initiation, the crack growth rate of the specimen is relatively slow under the action of stress. As the crack continues to expand, the magnitude and direction of the stress on the crack tip change and the stress situation becomes more complicated. The crack begins to branch and grows in different directions The metastable retained austenite in δ-TRIP steel undergoes phase transformation under the action of external force, which will absorb a lot of energy. At the same time, there are many large angle grain boundaries in the steel hindering the crack propagation. These two characteristics make the δ-TRIP steel has excellent fatigue performance.

In this paper, 347H stainless steel of three situation of solution, primary and secondary stabilizing with 0, 12, 24, 48 and 72 h accelerated sensitization heat treatment. The change of sensitization degree with time was studied by metallographic test, double-loop electrochemical potentiodynamic reactivation (DL-EPR) test, intergranular corrosion test and microscopic morphology observation. The result shows that the sensitization degree of the solution material increases rapidly and reaches the maximum value after 12h sensitization heat treatment. After that, it still belonged to severe sensitization situation, but the index gradually decreased. After stabilizing heat treatment, the sensitization degree of the material is lower than the situation of solution. After heat treatment for 48h, the material located on “possible sensitization” range, and the sensitization degree of the secondary stabilized material was always lower than is of the primary. It indicates that the sensitization of materials can not be completely inhibited by stabilizing heat treatment, and other anti-corrosion measures should be considered.

Metal matrix syntactic foams are consisting of metal matrix and hollow spheres in closely or randomly packed, which own multifunctional properties with lightweight, damping, heat insulation, energy absorption and have a vast application prospect. Steel matrix can extend the potential of syntactic foams as a materials class to several new fields of application. In this paper, the hollow alumina spheres were introduced into the steel matrix by infiltration casting, the minimum diameter of hollow spheres for infiltration is analyzed in theory, the steel matrix syntactic foams were successfully prepared, which contain two different sphere types with average diameter sizes 3.97mm and 4.72mm, and the average densities of syntactic foams were calculated to be 4.39 (spheres occupy 43.7% of the volume) and 3.74 g/cm3 (spheres occupy 52.1% of the volume), respectively. The microstructure characteristics of the steel matrix syntactic foam were analyzed by means of scanning electron microscopy and energy spectrum.

As a new type composite material, steel-based porous materials presented the higher stiffness, strength and higher temperature resistance in comparison with the nonferrous metals. In order to realize the free-design of pore structure and free-control of porosity of steel-based porous material, indirect 3D printing technology combined with the investment casting process has been used to fabricate the steel-based porous materials. The finite element method has been carried out to study the relationship between the porosity and the mechanical properties by quasi-static compression simulation, which is consistent with compression test. The modified Gibson-Ashby formula is used to establish the quantitative relationship between porosity and elastic modulus and yield strength of steel-based porous materials based on Kelvin structure.

Three-inch 6H-SiC bulk crystals were grown by the PVT method on the seeds processed by different treatments. The influences of seed surface morphology and subsurface damage on the dislocation density were investigated. The seed surface morphology was characterized by atomic force microscopy (AFM). The extent of the subsurface damage was estimated by electron back-scattered diffraction (EBSD) and Band Contrast (BC) value. The distribution and density of the dislocations were observed by optical microscopy (OM). The results showed that the pit density performed by H2 1400°C etching was nearly one order of magnitude lower than that by mechanical polishing (MP) process. So H2 etching processed at 1400°C for 2h could completely remove the subsurface damage, compared with the MP process with the deep surface damage.

Different nitrogen-doped 4H-SiC single crystals were grown by the physical vapor transport method through mixing nitrogen gas to the argon growth atmosphere in the composition range from 0% to 10%. The electrical properties of the crystals, including resistivity and mobility were measured by Hall effect and contactless eddy current measurements. The Raman spectra of different N-doped 4H-SiC single crystals were investigated from 173 to 473 K. The temperature and doping dependence of optical modes was analyzed with anharmonic effect. The phonon lifetime was derived from the linewidths of Raman spectra via the energy-time uncertainty relation.

Bulk 4H-SiC crystals were grown on 4° off-axis seeds by the physical vapor transport technique. Two completely different surface morphologies of as-grown crystals were observed by laser scanning confocal microscopy. The formation mechanisms of the different surface morphologies are proposed and discussed. We found that the facet formation and migration on the 4° off-axis seeds largely depended on the profile evolution of the temperature field in the growth cell over a long-term growth run. At the interface between the two growth regimes, some grown-in defects, including micropipes, dislocations and polytype inclusions, were frequently observed by polarizing optical microscopy and chemical etching. The stress induced by step coalescence could be responsible for the formation of these grown-in defects.

Illegal cooked oil is a serious food safety issue in China, while an effective authentication method is still lacking. In this paper, a microfluidic device was applied for the discrimination of low-grade oil from edible oil, by creating water droplets of different sizes in different oils.

This paper models the hydrodynamic focusing performance of a micro-fluidic chip with rectangular cross-sections, and the relationships between the aspect ratio, flow rate ratio of sheath flows to the sample flow, and dimensions and position of the focused sample flow are obtained. The simulation results are consistent with theoretical outcomes. And preliminary experiments were carried out to prove the simulation results.

To develop Al-Si cast alloys with high performance is important for lightweighting vehicles. In this study, the effects of the alloying elements such as Si, Cu, Mg contents (5%-7% Si, 1%-3%Cu, 0.3%-0.9%Mg) on mechanical properties of a test Al-Si-Cu-Mg cast alloy was studied to achieve a specific composition. The experimental results show that the Al-6%Si-3%Cu-0.3%Mg alloy has better comprehensive mechanical properties after T6 heat treatment, which indicates a remarkable interaction of the alloying elements for improving performance.

Anisotropic mechanical behavior is one of the key factors restricting the processing procedure of magnesium alloys. This pronounced anisotropy, however, cannot be characterized by classical isotropic or kinematic hardening due to the constant shape of yield surfaces during plastic deformation. Therefore, the shape evolution of yield surfaces, also known as distortional hardening is the main way to capture the anisotropic behavior. Based on elasto-plasticity theory at finite strain, constitutive model with distortional hardening for Mg alloys is proposed. The thermodynamical consistency is proved. The anisotropic mechanical behavior of AZ31 sheet is demonstrated after material parameters calibration.

Automatic Target Recognition (ATR) system is widely utilized in engineering. However, the performance evaluation method for an ATR system is limited. This paper resolves the problem based on the theory of Sugeno fuzzy integration. The performance metrics are firstly measured. Then, a performance evaluation model is developed. Simulation result shows that, compared to the existing technologies, the novel method can offer more objective performance conclusions for an ATR system.

Dams can effectively alleviate great debris flow hazards to downstream regions, so they has been widely applied to prevention and control engineering of debris flow disaster now. A kind of steel-concrete combined structure with steel braces was presented based on conventional gravity dams, and the superiority of the new structure in terms of impact resistance was verified contrastively by means of model experiments under solid impact. The results show that braces can restrain cracks and reduce their width, thus the extent of damage in impact areas is alleviated effectively. Compared with the conventional dam, the dynamic strains and acceleration peak values of the dam with braces both observably reduce, and the highest reduction ranges of them may be up to 69.2% and 47.8% respectively, so the deformation and vibration are limited by the braces. The dynamic displacement peak values of the new-type dam are significantly less than the conventional dam, and the average reduction range of this index can reach to about 46%, so the structural stiffness has been enhanced by a large margin.

The general characteristic of current plate heat exchangers is first summarized in this paper. A new plate exchanger of multi-stream under high pressure is proposed, which is composed of the plates with opening the gyroidal flow-trough along the radius and the shell, it has some advantages, such as simple structure, high efficiency and available under high pressure. We introduce the structure of the plate, the shell and the slotting types. In addition, the process calculation method of heat-transfer is given and the strength calculation method for the key components of the novel exchanger is also presented. According to the stress analysis to the plate wall with ANSYS software, we have proved the reliability of the calculation method.

Organochlorine pesticides have had a wide and long history of applications in many countries around the world, which cause serious environmental problems. Constructed wetlands are considered an effective means of removal of organochlorine pesticides. This study describes the constructed wetland and applications of organochlorine pesticides contamination in constructed wetlands, and focuses on purification for organochlorine pesticides of microorganisms and plants in constructed wetlands. Then discussed constructed wetlands removal influence factors of organochlorine pesticides. And put forward some recommendations in research.

Water quality criteria (WQC) is based on the results of scientific experiments and inferences, which prescribe a limit threshold value to pollutants and other harmful factors in water. The system of water quality criteria study is basically a blank circumstance. It’s urgent to establish water quality criteria to adapt with the characters of China water environment to supply theoretic bases for revising water quality standards and managing environment. In this paper, an overview of the water quality criteria, as well as domestic and foreign research progress in theoretical methodology are systematically discussed, furthermore, considering current status of water quality criteria, comprehensive research were pointed out to be done in the future.

The article analyzes the current situation of city infrastructure construction in China, elaborated needs if our country city infrastructure construction projects in various stages of information management, a framework of information platform are presented for city infrastructure projects of our construction comprehensive control, and efficient management city infrastructure construction project, and provide collaboration platform for the party in the infrastructure construction projects.

Here, we developed single crystalline Cu@C nanowires with fivefold twinned structure via a facile hydrothermal method. In situ uniaxial tension tests of these NWs performed in transmission electron microscopy chamber reveal the ultrahigh strength (as much as 6.2 GPa) accompanied by favorable ductility (elongation>15%). The excellent performances benefit from nanoscale dimensions, unique penta-twinned geometry and good crystalline quality with protection of carbon shells. The study also provides direct experimental evidence for the theoretical modeling on the deformation mechanisms of metallic nanowires that have appeared in recent years. We expect that these findings can open a new window for applications in micro-or nanoelectromechanical devices where superior mechanical performances are desirable.

Methylene blue is an organic dyestuff and damaged to human beings. Graphene-based composite is a new type of nanometer materials and with outstanding adsorption capacity of methylene blue than other materials in aqueous solution. This paper summarized and compared the difference among graphene, graphene-based composites and other materials in removing methylene blue in aqueous solution.

The considerable variability of architecture and function realization of smart substation, which differ from traditional substations, makes the range of protection function check no longer restricted to one device, so it is necessary to carry out thorough monitoring and testing for various inks of functional implementation [1-2]. For this purpose, the automatic checking of protection functions for smart substation is researched, and a scheme for the implementation of the automatic checking is designed [3-4]. By means of adding various checking manners to application software implementation of the devices of protection system for smart substation, the checking and detection of various function implementation links of the protection system are performed, and by use of the expert system based on Dempster-Shafer theory a real-time virtual checking scheme is configured and through real-time analysis on checking information the conclusion of the checking is obtained. The proposed scheme enhances the self-diagnosis and self-monitoring ability of protection system for smart substation and gives full play to the superiority in digital information acquisition and information interaction of digital substation, so it can be used to the checking during on-site commissioning, besides, partial functions can be also used to perform on-line monitoring of protections being operated [5-9].

Contrapose the difficulties of C/S (client/server) framework redundant switching, the great quantity of synchronic data, heavy load of the network, needs to be updated shock, etc, based on the working mode and characteristic of C/S framework Power plant and substation automation system to conduct in-depth analysis, an optimized design scheme of C/S framework automation system of Power plant and substation was proposed.

Based on the theory of bone conduction, a novel circular piezoelectric bone conduction hearing device with a new structure of leaf spring support and excellent low-frequency response is proposed in this paper. The simulation analysis of the circular piezoelectric vibrators with different support ways was carried by ANSYS. And the prototype of piezoelectric bone conduction headphone supported by the optimal way was produced. The experimental test was conducted and the results showed that the maximum response amplitude of headphone could reach up to 26.14μm in the low frequency region ranging from 20Hz to 1000Hz. The zero-distance loudness of the headphone is between 60dB and 90dB, and the 1m close distance loudness is between 30dB and 40dB.The experimental results confirmed that the headphone can meet the hearing needs without healthy risk and ambient noise.

The example which is selected in this engineering project is the hospital in Lanzhou University of Technology, the paper analyzed the reason that the foundation subsidence, and used reasonable and effective method on reinforcement. It hoped that the achievement can provide beneficial reference for handling the problem that foundation subsidence in collapsible loess areas.

This paper further investigates the problem of synchronization of hyperchaotic memristor-based Chua’s circuits. An active control method is employed to design a controller to achieve the global synchronization of two identical memristor-based systems. Based on Lyapunov stability theory, a sufficient condition is given to guarantee the stability of the synchronization error system.

In the present code, the embedded depth is determined on the multi-pivot support structure to consider the impact of seepage less, and it is verified by anti-seepage stability for single layer aquifer, while the embedded depth is determined not expressly provide for heterogeneity aquifer of the coefficient of permeability difference. However, in the northwest loess areas, the formation is complex, permeability coefficient is variations. To solve this problem, the arctic investigates change law that the impacts of embedded depth variation change on bending moment, the vertical displacement of bottom and maximum flow velocity under seepage, and made a qualitative research model. And the impact of seepage on the embedded depth cannot be ignored and a greater impact on the stability of the pit.

This Paper introduces the complete process of data provenance tracing for transformation diagram based on Wivern: at first, we construct the candidate weak derivation-sets using continued-tracing weak inverse attribute mapping, then verify them according the type and property of transformation and attribute mapping.

With the rapid development of the Smartphone in recent years, it has been a popular personal mobile communication device. How to make the Smartphone be a better service for our lives is an important direction of research in our smart home. This article describes how to integrate the Android, Bluetooth technology into the control of lighting equipment to realize the lighting equipment’s power automatic switching.

For more accurate evaluation of the static contact angle, the height-width method and circle fitting algorithm are investigated, the comparison of some factors on the two algorithms are analyzed, including difficulties of programming, computational complexity, influence of dimensionless drop volume, contact angle and edge noise on accuracy. The critical dimensionless drop volumes corresponding to a contact angle error of 3° are given. The results indicate that: the programming of height-width method is more difficult than that of the circle fitting algorithm, the computational complexity of the height-width method is less than that of the circle fitting algorithm. The errors of the two algorithms increase with the drop volume and contact angle, the height-width method is more accurate than that of the circle fitting algorithm, the errors acceleration decrease/increase with the drop volume/contact angle. The critical dimensionless drop volumes of the two algorithms decrease as the contact angle increases, and them will tend to saturation. The noise-resistant capacity of the circle fitting algorithm is better that the height-width method. Therefore, the circle fitting algorithm should be selected in the condition of high noise level. Otherwise the height-width method should be selected.

Organochlorine Pesticides (OCPs) is a kind of typical Persistent Organic Pollutants (POPs) with high toxicity, semi-volatility, environmental persistence and bio-magnification. Because of its large number of application in history, the residue level of OCPs in environmental media is rather high. This paper summarizes the existing status of the residue level and distribution of OCPs in China’s lakes in recent years, which is helpful to evaluate the pollution status of the OCPs in lake and provides a basis for effective governance.

In order to eliminate the mixed crystals of the thick-walled heavy cylinder after rolling and improve the quench shortage of tank copious cooling, it is significant to analyze the cooling capacity of spray cooling and tank copious cooling. Models of heat transfer coefficient about spray cooling and copious cooling were established. The quenching process simulation was made based on the DEFORM software. The cooling rate models of center part about spray cooling and copious cooling were build. According to the CCT curves of heavy cylinder material and simulation results, which show that: (1) Using spray cooling can increase the cooling rate of center part to some extent and improve the mechanical properties. (2) The maximum capacity of spray cooling is 280mm, that is the microstructure of center part fully transfers to bainite, which is 50mm larger than copious cooling.

This paper introduces a practical and cross-platform virtual electrical experimental tool (VEET) based on an off the shelf game engine called Unity3D which is powerful and flexible to develop Virtual and Augmented Reality (VR/AR) applications. Taking the electrical experiments of technological university as examples, the well designed virtual experimental system has the characteristics of lifelike three dimensional (3D) experimental environments, AR interactive interface on mobile devices, intelligent detecting mechanism and cross-platform. We described VEET’?s flexible design and demonstrate its use in teaching where 120 students from three classes conducted electrical experiments with it. The experiments in VEET were presented on desktop, mobile and web browser using low cost common devices (personal computer, android handheld device, Chrome browser). Evaluating the main performance parameters, the well practicability was confirmed.

A dynamic calculation model of the pile supporting structure with single prestressed anchor for the slope is proposed in this paper. The motion equation of the pile-prestressed anchor is established and the analytical solutions are obtained. In addition the proposed method is applied to a project case to carry out the seismic analysis and design of the pile supporting structure with single prestressed anchor. The calculation model provides a new approach for earthquake analysis and seismic design of slope supported by pile supporting structure with pre-stress anchor.

Salt expansion was the main diseases of the salty foundation. In order to study the deformation regularity and quantitative description of coarse particles saline soil ground in natural condition, a field test was conducted in Dunhuang area. The exploratory well with 7.5 m depth (deeper then annual temperature change layer) was excavated on site, and the data of salt content \water content \ground temperature \salt expansion rate were collected. From the test it was found that : salt expansion mainly decided by salt content, salt content and salt expansion rate have approximately a quadratic function relationship; the minimum salt content could cause soil expansion is 1.5‰; The salt expansion force was strong, and the gravitational stress could not suppress the deformation.

The purpose of this study is to investigate the catalytic effects of different metals in Shengli lignite on the char reactivity. The pyrolysis of Shengli lignite and various metal catalyst loaded coal was investigated in a small fixed-bed reactor, and the gasification activity with steam for different chars was compared as well. The results show that Fe, Ni, Ca and K could effectively lowering the gasification temperature, enhancing the gasification reactivity of SL char. Alkali (K) and alkaline earth (Ca) could be feasibly used as catalysis for the catalytic steam gasification at relatively low temperatures (550~700°C) to produce gases with high H2 (63.2~63.8 v%) and low CO (below 0.9%), and promoting the carbon-water reaction, the water-gas shift reaction to some extent.

Oxygen adsorption and CO2produced of samples at different adsorption temperatures was investigated, Combined with thermal analysis method, the combustion properties of coal samples was determined. The results show that the oxygen adsorption capacity and CO2produced of the samples increase and later decrease with the enhanced of pyrolysis degree. In the process of low-temperature oxidation, coal molecular side chains break, then H2O, CO, CO2and so on are detected in turn; with the enhanced of pyrolysis degree, it reveals that combustion reaction activity decreased and spontaneous combustion tendency weakened.

The main objective of this work is to compare the different fracture behavior of carbon fiber-reinforced composite T300/epoxy with cross-play composite laminate. Tension-tension and three points bending fatigue are adopted, with optical microscopic and scanning electron microscopic observation of the specimen fracture surfaces. The specific objectives are: a) for tension-tension fatigue loading, the onset and multiplication of transverse matrix cracks continuously improve the delamination. Consequently, fibers rupture occurs in this locally region with high density of cracks. b) The density of intralaminar cracks increases with number of fatigue cycles. c) During the shear stress distribution under three points bending fatigue, delamination which is the main characteristic of T300/epoxy, initiates from the central and propagates alone the neutral axis of the sample. And a small quantity of fiber breakage occurs in the maximal compress region.

Using the frame supporting structure of pre-stressed anchor bolt seismic strengthening technology reinforced the instability of gravity retaining wall. Earth pressure of retaining wall in seismic reinforcement after shall take between active and static earth pressure for the form of the distribution . In this paper, based on the limit equilibrium theory, and the whole stability for retaining walls is analysis, the theoretical formula of the stability safety factor between stability against slope and overturning safety factor is derived. By calculation and comparative analysis with an example, the stability safety factor of gravity retaining wall with introducing this strengthening technology is improved obviously. Keywords: frame anchor structure; seismic strengthening; anti-slip and anti-overturning; stability coefficient

In this paper, a clock domains cross FIFO interface of multichannel continuous DDR2 read and write is designed. The interface provides continuous data stream from DDR2 to 12 different channels simultaneously. Four core issues are resolved: mismatch on bit width between DDR2 user interface and the channels, data stream conversion control from DDR2 to channels, clock domains difference between DDR2 and channels, Discontinuous process of DDR2 read and write. DDR2 storage spaces are partitioned for matching data width of the DDR2 user interface and the channels, and to achieve the maximum utilization of the DDR2 memory. Via state machine, data conversion and synchronization from DDR2 to channels are implemented, and the state machine can be applied to providing continuous DDR2 data to any numbers of channels simultaneously. Cross clock domains FIFO interface goes to solve the different clock domains problem between channels and DDR2. When bank or row addresses conversion occurs, or DDR2 auto-refresh cycle comes, DDR2 cannot be read or written, leading to data interruptedly in time aspect. To solve the problem, the FIFO interface is designed followed the full-mode handshake protocol. Through the interface caching, the 12 channels can continuously read data from the DDR2 simultaneously. The final design can achieve the goal that under the fastest case, DDR2 provides 12 channels data stream simultaneously at 61.538 MHz rate at the same time, and 90.566% efficiency in the reading and writing aspects.

Graphene and its derivatives have become great concern in biomedical fields. Though many investigations about their toxicity have been reported, investigation on the interaction with γ-globulins is lacking. In this work, we studied the effects of the graphene oxide (GO) on the structure of γ-globulins by UV absorption spectra, circular dichroism (CD) and fuorescence spectra. The results showed that GO could alter the secondary structures and conformation. The results obtained in this study provided good insight into understanding the biomedical application of GO in vivo.

The psychology of utility of the agent in government investment projects is studied from the psychological point of view in this paper. Combining the game theory with the deterrence theory, we establish the applied technology named deterrence game model which is used to predict the behavioral intention of the agent. Then according to the specific actions of the agent during the construction,we adjust to exert a certain deterrence which is expected to restrain and guide the behavior of the agent,which makes the whole process supervision of government investment projects under control.This paper demonstrates the effectiveness of the applied technology.

The face of the valve seat sealing surface design, the finite element analysis and calculation of ball valve seat sealing surface and angle of the design method is studied. Through 3D CAD technology for ball valve design, guide 3D design model to finite element analysis software to calculate ,reveal the sealing load distribution of pressure in the valve seat sealing surface, sealing pressure values are obtained, through the valve seat sealing surface design Angle analysis, to obtain the optimal value of sealing surface angle.

With the national policy changes, pharmaceutical distribution companies using information technology to improve the competitiveness of enterprises was imperative. This paper took TAM and TOE as theoretical framework. And then combined pharmaceutical distribution business characteristics，the pharmaceutical distribution enterprise IT adoption influencing factors model was conducted with technical, organizational and environment organizational characteristics. The empirical results supported that relative advantages, compatibility, complexity, firm characteristic, leadership support, human resources investment, information technology strategy, relation of competition and cooperation, and government support had great influence on enterprise adoption.

According to the process of the ECG signal extraction, the ECG signal is susceptible to interference which will affect the quality and effect of ECG test. In this essay, we designed an ECG signal filtering system based on ARM. It can filter the interference signal and reduce the interference of the common mode signal and power frequency, through the design circuit of the preamplifier, post amplification, filtering, notch filtering, and power amplification. Thus, ECG signal will be better collected and met the best demand.